Stretchable display device

ABSTRACT

A stretchable display device comprises a lower substrate; a plurality of island substrates where a plurality of pixels is defined, spaced apart from each other and disposed on the lower substrate and; a plurality of connecting lines electrically connected to a plurality of pads disposed on adjacent island substrates among the plurality of island substrates, wherein the plurality of connecting lines has a curved shape; and a plurality of conductive reinforcing members in contact with a portion of each connecting line.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of Korean Patent Application No.10-2018-0084928 filed on Jul. 20, 2018, in the Korean IntellectualProperty Office, which is incorporated by reference in its entirety.

BACKGROUND Field of the Disclosure

The present disclosure relates to a display device, and moreparticularly, a stretchable display device. Although the presentdisclosure is suitable for a wide scope of applications, it isparticularly suitable for improving reliability that can suppress damageon signal lines even if the device is bent or stretched and can stablyprovide electrical signal even if the signal lines are damaged.

Description of the Background

An Organic Light Emitting Display (OLED) that emits light by itself, aLiquid Crystal Display (LCD) that requires separate light sources, etc.are used as the display devices used in a computer monitor, a TV, and amobile phone.

Display devices are being applied to more and more varied fieldsincluding not only a computer monitor and a TV, but personal mobiledevices, and a display device having a wide active area and reducedvolume and weight is being studied.

Recently, a stretchable display device manufactured to be able tostretch/contract in a specific direction by users and change intovarious shapes by forming a display unit, lines, etc. on a flexiblesubstrate such as plastic that is a flexible material has beenspotlighted as a next generation display device.

SUMMARY

The present disclosure is to provide a stretchable display device thatcan be bent or stretched without damaging display elements disposed on aplurality of rigid substrates by disposing a plurality of rigidsubstrates on which a plurality of pixels is disposed and spaced over aflexible substrate.

In addition, the present disclosure is to provide a stretchable displaydevice that can minimize damage to a connecting line even though thedisplay device is bent or stretched by disposing a connecting lineincluding conductive particles between a plurality of island substratesspaced apart from each other on which a plurality of pixel is defined.

The present disclosure is to provide a stretchable display device inwhich pads disposed on a plurality of island substrates are electricallyconnected with each other by conductive particles and the conductiveparticles can connect the pads in a straight shape, by including a basepolymer and conductive particles distributed in an upper portion of thebase polymer and having density that decreases with distance from theuppermost surface of the base polymer, each between a plurality ofisland substrates.

The present disclosure is to provide a stretchable display device thatcan improve or reduce damage to a connecting line by minimizing aphysical step between several components on a plurality of islandsubstrates and a lower substrate by connecting pads on a plurality ofisland substrates and including a conductive reinforcing member made ofa metal material and disposed over or under the connecting line.

Further, the present disclosure is to provide a stretchable displaydevice in which damage to a connecting line at a point where stressapplied to the connecting line is maximized is minimized and electricalsignal transmission can be smoothly maintained when the connecting lineis damaged, by disposing a conductive reinforcing member over or underthe connecting line at a peak area of a connecting line having a curvedshape or at the inner edge of the peak area.

The present disclosure is not limited to the above-mentioned objects,and other objects, which are not mentioned above, can be clearlyunderstood by those skilled in the art from the following descriptions.

In order to achieve the above-mentioned aspects, a stretchable displaydevice comprises a lower substrate; a plurality of island substrateswhere a plurality of pixels is defined, spaced apart from each other anddisposed on the lower substrate and; a plurality of connecting lineselectrically connected to a plurality of pads disposed on adjacentisland substrates among the plurality of island substrates, wherein theplurality of connecting lines has a curved shape; and a plurality ofconductive reinforcing members in contact with a portion of eachconnecting line.

In another aspect of the present disclosure, a stretchable displaydevice comprises a lower flexible substrate; a plurality of rigidsubstrates where a plurality of pixels is defined, spaced apart fromeach other and disposed on the lower flexible substrate; a plurality ofconnecting lines electrically connected to a plurality of pads disposedbetween adjacent rigid substrates among the plurality of rigidsubstrates, and are made of a same material as a plurality of conductivecomponents disposed on the plurality of rigid substrates; and aplurality of conductive flexible layers disposed on one of a top surfaceand a bottom surface of the plurality of connecting lines.

Other detailed matters of the exemplary aspects are included in thedetailed description and the drawings.

The present disclosure has an effect that since the plurality of islandsubstrates that is rigid substrates is disposed on the lower substratethat is a flexible substrate, the stretchable display device can beeasily bent or stretched.

The present disclosure has an effect that since the connecting linesconnecting pads of the plurality of island substrates include a basepolymer and conductive particles, even if the connecting lines are bentor stretched, the connecting lines are not easily damaged, electricalsignals can be transmitted by the conductive particles, and theconnecting lines can be formed in a straight shape.

The present disclosure has an effect that since the top surface of thebase polymer of the connecting lines connecting the pads of theplurality of island substrates is made flat or formed to cover all theplanarization layers on the island substrates, it is possible tomaintain the flexible characteristic, reduce the process cost and time,and minimize damage to conductive paths formed by the conductiveparticles of the connecting lines.

The present disclosure has an effect that since the base polymer of theconnecting lines connecting the pads of the plurality of islandsubstrates is formed only in the areas overlapping the conductiveparticles of the connecting lines, conductive paths by adjacentconductive particles are connected to each other, so disconnection ofeach of the conductive paths can be minimized.

The present disclosure has an effect that since the conductivereinforcing members are disposed adjacent to the plurality of islandsubstrates under or over the connecting lines having a curved shape, itis possible to minimize damage such as cracking of the connecting lines.

The present disclosure has an effect that since the conductivereinforcing members are disposed over or under the connecting lines inthe peak areas of the connecting lines having a curved shape or at theinner edges of the peak areas, it is possible to minimize damage to theconnecting lines due to stress applied to the connecting lines, and itis possible to suppress blocking of electrical signals when theconnecting lines are damaged.

The effects according to the present disclosure are not limited to thecontents exemplified above, and more various effects are included in thepresent specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is an exploded perspective view of a stretchable display deviceaccording to an aspect of the present disclosure;

FIG. 2 is an enlarged plan view of the stretchable display deviceaccording to an aspect of the present disclosure;

FIG. 3 is a schematic cross-sectional view of one subpixel of FIG. 1;

FIG. 4A and FIG. 4B are enlarged cross-sectional views of area A andarea B of FIG. 3;

FIG. 5 is a schematic cross-sectional view of one subpixel of astretchable display device according to another aspect of the presentdisclosure;

FIG. 6 is a schematic cross-sectional view of one subpixel of astretchable display device according to another aspect of the presentdisclosure;

FIG. 7 is an enlarged plan view of a stretchable display deviceaccording to another aspect of the present disclosure;

FIG. 8 is an enlarged plan view of a stretchable display deviceaccording to another aspect of the present disclosure;

FIG. 9 is an enlarged plan view of a stretchable display deviceaccording to another aspect of the present disclosure;

FIG. 10 is a cross-sectional view schematically showing one subpixel ofthe stretchable display device of FIG. 9;

FIG. 11 is a schematic cross-sectional view of one subpixel of astretchable display device according to another aspect of the presentdisclosure;

FIG. 12 is a schematic cross-sectional view of one subpixel of astretchable display device according to another aspect of the presentdisclosure;

FIG. 13 is an enlarged plan view of a stretchable display deviceaccording to another aspect of the present disclosure;

FIG. 14A and FIG. 14B are cross-sectional views taken along lineXIV-XIV′ of FIG. 13; and

FIG. 15 is a schematic cross-sectional view showing one subpixel of astretchable display device according to another aspect of the presentdisclosure.

DETAILED DESCRIPTION

Advantages and characteristics of the present disclosure and a method ofachieving the advantages and characteristics will be clear by referringto exemplary aspects described below in detail together with theaccompanying drawings. However, the present disclosure is not limited tothe exemplary aspects disclosed herein but will be implemented invarious forms. The exemplary aspects are provided by way of example onlyso that those skilled in the art can fully understand the disclosures ofthe present disclosure and the scope of the present disclosure.Therefore, the present disclosure will be defined only by the scope ofthe appended claims.

The shapes, sizes, ratios, angles, numbers, and the like illustrated inthe accompanying drawings for describing the exemplary aspects of thepresent disclosure are merely examples, and the present disclosure isnot limited thereto. Like reference numerals generally denote likeelements throughout the specification. Further, in the followingdescription of the present disclosure, a detailed explanation of knownrelated technologies may be omitted to avoid unnecessarily obscuring thesubject matter of the present disclosure. The terms such as “including,”“having,” and “consist of” used herein are generally intended to allowother components to be added unless the terms are used with the term“only”. Any references to singular may include plural unless expresslystated otherwise.

Components are interpreted to include an ordinary error range even ifnot expressly stated.

When the position relation between two parts is described using theterms such as “on”, “above”, “below”, and “next”, one or more parts maybe positioned between the two parts unless the terms are used with theterm “immediately” or “directly”.

When an element or layer is disposed “on” another element or layer,another layer or another element may be interposed directly on the otherelement or therebetween. The terms “lower”, “higher”, “upper”, “bottom”and “top”, where referring to spatial positioning, are referenced to thetypical orientation from which the display is viewed. That is to saythat “higher”, “upper” and “top” are closer to the typical viewingsurface than “lower” and “bottom”.

Although the terms “first”, “second”, and the like are used fordescribing various components, these components are not confined bythese terms. These terms are merely used for distinguishing onecomponent from the other components. Therefore, a first component to bementioned below may be a second component in a technical concept of thepresent disclosure.

Like reference numerals generally denote like elements throughout thespecification.

A size and a thickness of each component illustrated in the drawing areillustrated for convenience of description, and the present disclosureis not limited to the size and the thickness of the componentillustrated.

The features of various aspects of the present disclosure can bepartially or entirely adhered to or combined with each other and can beinterlocked and operated in technically various ways, and the aspectscan be carried out independently of or in association with each other.

Hereinafter, exemplary aspects of the present disclosure will bedescribed in detail with reference to accompanying drawings.

<Stretchable Display Device>

A stretchable display device may be referred to as a display device thatcan display images even if it is bent or stretched. A stretchabledisplay device can have high flexibility, as compared with theconventional display devices. Accordingly, the shape of the stretchabledisplay device can be freely changed in accordance with operation by auser such as bending and stretching the stretchable display device. Forexample, when the user holds and pulls an end of a stretchable displaydevice, the stretchable display device can be stretched by the force ofthe user. Alternatively, when a user puts a stretchable display deviceon an uneven wall, the stretchable display device can be disposed to bebent in the surface shape of the wall. Further, when the force appliedby a user is removed, a stretchable display device can return to theinitial shape.

FIG. 1 is a plan view showing a display device according to an aspect ofthe present disclosure. Referring to FIG. 1, a stretchable displaydevice 100 includes a lower substrate 110A, a plurality of islandsubstrates 111, connecting lines 170, chip on films (COF) 120, a printedcircuit board (PCB) 130, an upper substrate 110B, and a polarizing plate119. An adhesive layer for bonding the lower substrate 110A and theupper substrate 110B are not shown in FIG. 1 for the convenience ofdescription.

The lower substrate 110A is a substrate for supporting and protectingvarious components of the stretchable display device 100. The lowersubstrate 110A, which is a flexible substrate, may be made of a bendableor stretchable insulating material. For example, the lower substrate110A may be made of silicon rubber such as polydimethylsiloxane (PDMS)and an elastomer such as polyurethane (PU), so it has flexibility. Thematerial of the lower substrate 110A, however, is not limited thereto.

The lower substrate 110A, which is a flexible substrate, may bereversibly expandable and contractible. Further, an elastic modulus ofthe lower substrate 110A may be several to hundreds of MPa and aelongation fracture rate may be 100% or more. The thickness of the lowersubstrate 110A may be 10 μm to 1 mm, but is not limited thereto.

The lower substrate 110A may have an active area AA and a non-activearea NA surrounding the active area AA.

The active area AA is an area where images are displayed on thestretchable display device 100, and display elements and various drivingelements for driving the display elements are disposed in the activearea AA. The active area AA includes a plurality of pixels (see, e.g.,FIG. 2: “PX”) including a plurality of subpixels (see, e.g., FIG. 2:“SPX”). The plurality of pixels is disposed in the active area AA andincludes a plurality of display elements. The plurality of subpixelseach may be connected with various lines that transfers electricalsignals. For example, the plurality of subpixels each may be connectedwith various lines such as a gate line, a data line, a high-potentialpower line, a low-potential power line, and a reference voltage line.

The non-active area NA is an area adjacent to the active area AA. Thenon-active area NA may be an area disposed adjacent to the active areaAA and surrounding the active area AA. The non-active area NA is an areawhere an image is not displayed, and lines, circuit units, etc. may bedisposed in the non-active area NA. For example, a plurality of pads maybe disposed in the non-active area NA and each of the pads may beconnected with at least one subpixel of the plurality of subpixels inthe active area AA.

The plurality of island substrates 111 on which a plurality of pixelsare defined is disposed on the lower substrate 110A. The plurality ofisland substrates 111, which is rigid substrates, is spaced apart fromeach other and disposed on the lower substrate 110A. The plurality ofisland substrates 111 may be more rigid than the lower substrate 110A.That is, the lower substrate 110A may be softer or more flexible thanthe plurality of island substrates 111 and the plurality of islandsubstrates 111 may be more rigid than the lower substrate 110A.

The plurality of island substrates 111, which is a plurality of rigidsubstrates, may be made of a plastic material having flexibility and,for example, may be made of polyimide (PI), etc.

The modulus of the plurality of island substrates 111 may be higher thanthat of the lower substrate 110A. The modulus is an elastic modulusshowing a ratio of deformation of a substrate caused by stress appliedto the substrate, and when the modulus is relatively high, the hardnessmay be relatively high. Accordingly, the plurality of island substrates111 may be a plurality of rigid substrates that is more rigid than thelower substrate 110A. The modulus of the plurality of island substrates111 may be a thousand times or more than that of the lower substrate110A, but are not limited thereto.

The connecting lines 170 are disposed among the plurality of islandsubstrates 111. The connecting lines 170 may be disposed between thepads disposed on the plurality of island substrates 111 and mayelectrically connect each pad. The connecting lines 170 will bedescribed in more detail with reference to FIG. 2.

The COFs 120, which are films having various components on flexible basefilms 121, are components for supplying signals to the plurality ofsubpixels in the active area AA. The COFs 120 may be bonded to theplurality of pads disposed in the non-active area NA and supply a powervoltage, a data voltage, a gate voltage, etc. to each of the pluralityof subpixels in the active area AA through the pads. Each of the COFs120 includes a base film 121 and a driving IC 122 and may includevarious other components.

The base films 121 are layers supporting the driving ICs 122 of the COFs120. The base films 121 may be made of an insulating material, forexample, an insulating material having flexibility.

The driving ICs 122 are components that process data for displayingimages and driving signals for processing the data. Although the drivingICs 122 are mounted in the COF (120) in FIG. 1, the driving ICs 122 arenot limited thereto and may be mounted in the type of chip on glass(COG), tape carrier package (TCP), etc.

Controllers such as an IC chip and a circuit may be mounted on theprinted circuit board (PCB) 130. Further, a memory, a processor, etc.also may be mounted on the printed circuit board 130. The printedcircuit board 130 is a configuration that transmits signals for drivingthe display elements from the controllers to the display elements.

The printed circuit board 130 is connected with the COFs 120, so theycan be electrically connected with each of the plurality of subpixels onthe plurality of island substrates 111.

The upper substrate 110B is a substrate overlapping the lower substrate110A and protects various components of the stretchable display device100. The upper substrate 110B, which is a flexible substrate, may bemade of a bendable or stretchable insulating material. For example, theupper substrate 110B may be made of a flexible material and may be madeof the same material as the lower substrate 110A, but is not limitedthereto.

The polarizing plate 119, which is a configuration suppressing externallight reflection of the stretchable display device 100, may be disposedon the upper substrate 110B while overlapping the upper substrate 110B.However, the polarizing plate 119 is not limited thereto and, may bedisposed under the upper substrate 110B, or may be omitted, depending onthe configuration of the stretchable display device 100.

FIGS. 2-3 and FIGS. 4A-4B are referred to describe in more detail thestretchable display device 100 according to an aspect of the presentdisclosure.

<Planar & Cross-Sectional Structures>

FIG. 2 is an enlarged plan view of the stretchable display deviceaccording to an aspect of the present disclosure. FIG. 3 is a schematiccross-sectional view of a subpixel of FIG. 1. FIG. 4A and FIG. 4B areenlarged cross-sectional views of area A and area B of FIG. 3.

Referring to FIGS. 2 and 3, the plurality of island substrates 111 isdisposed on the lower substrate 110A. The plurality of island substrates111 is spaced apart from each other and disposed on the lower substrate110A. For example, the plurality of island substrates 111, as shown inFIGS. 1 and 2, may be disposed in a matrix shape on the lower substrate110A, but is not limited thereto.

Referring to FIG. 3, a buffer layer 112 is disposed on the plurality ofisland substrates 111. The buffer layer 112 is formed on the pluralityof island substrates 111 and protects various components of thestretchable display device 100 against permeation of water (H₂O) andoxygen (O₂) from the outside from the lower substrate 110A and theplurality of island substrates 111. The buffer layer 112 may be made ofan insulating material, and for example, may be made of a singleinorganic layer or a multi-inorganic layer made of a silicon nitride(SiNx), a silicon oxide (SiOx), silicon oxynitride (SiON), etc. However,the buffer layer 112 may be omitted, depending on the structure orcharacteristics of the stretchable display device 100.

The buffer layer 112 may be formed only in the areas overlapping theplurality of island substrates 111. As described above, since the bufferlayers 112 may be made of an inorganic material, they may be easilydamaged, such as cracking, when the stretchable display device 100 isstretched. Accordingly, the buffer layer 112 is patterned in the shapeof the plurality of island substrates 111 without being formed in theareas between the plurality of island substrates 111, and it can beformed only over the plurality of island substrates 111. Therefore,since the buffer layer 112 is formed only in the areas overlapping theplurality of island substrates 111 that is the rigid substrates, it ispossible to suppress damage to the buffer layer 112 even though thestretchable display device 100 according to an aspect of the presentdisclosure is deformed, such as, bending or stretching.

Referring to FIG. 3, a transistor 140 including a gate electrode 141, anactive layer 142, a source electrode 143, and a drain electrode 144 isformed on the buffer layer 112. For example, the active layer 142 isformed on the buffer layer 112, and a gate insulating layer 113 forinsulating the active layer 142 and the gate electrode 141 from eachother is formed on the active layer 142. An inter-layer insulating layer114 is formed to insulate the gate electrode 141, the source electrode143, and the drain electrode 144 from each other, and the sourceelectrode 143 and the drain electrode 144 that are in contact with theactive layer 142 are formed on the inter-layer insulating layer 114.

The gate insulating layer 113 and the inter-layer insulating layer 114may be formed only in the areas overlapping the plurality of islandsubstrates 111 by patterning. The gate insulating layer 113 and theinter-layer insulating layer 114 may also be made of an inorganicmaterial, as may the buffer layer 112, so they may be easily damagedsuch as cracking when the stretchable display device 100 is stretched.Accordingly, the gate insulating layer 113 and the inter-layerinsulating layer 114 are patterned to have the shape of the plurality ofisland substrates 111 without being formed in the areas between theplurality of island substrates 111, whereby they can be formed only onthe plurality of island substrates 111.

Only a driving transistor of various transistors that may be included inthe stretchable display device 100 is shown in FIG. 3 for theconvenience of description, but a switching transistor, a capacitor,etc. may be included in the display device. Further, although thetransistor 140 is described as having a coplanar structure in thisspecification, various transistors, for example, having a staggeredstructure also may be used.

Referring to FIG. 3, a gate pad 161 is disposed on the gate insulatinglayer 113. The gate pad 161 is a pad for transmitting a gate signal to aplurality of subpixels SPX. The gate pad 161 may be made of the samematerial as the gate electrode 141, but is not limited thereto.

Referring to FIG. 3, a planarization layer 115 is formed on thetransistor 140 and the inter-layer insulating layer 114. Theplanarization layer 115 planarizes the top of the transistor 140. Theplanarization layer 115 may be composed of a single layer or a pluralityof layers and may be made of an organic material. For example, theplanarization layer 115 may be made of an acrylic-based organicmaterial, but is not limited thereto. The planarization layer 115 mayhave a contact hole for electrically connecting the transistor 140 andan anode 151, a contact hole for electrically connecting a data pad 163and the source electrode 143, and a contact hole for electricallyconnecting a connecting pad 162 and a gate pad 161.

In some aspects, a passivation layer may be formed between thetransistor 140 and the planarization layer 115. That is, a passivationlayer covering the transistor 140 may be formed to protect thetransistor 140 from permeation of water, oxygen, etc. The passivationlayer may be made of an inorganic material and may be composed of asingle layer or a multi-layer, but is not limited thereto.

Referring to FIG. 3, the data pad 163, the connecting pad 162, and theorganic light emitting element 150 are disposed on the planarizationlayer 115.

The data pad 163 can transmit a data signal from a connecting line 170,which functions as a data line, to a plurality of subpixels SPX. Thedata pad 163 is connected with the source electrode 143 of thetransistor 140 through a contact hole formed at the planarization layer115. The data pad 163 may be made of the same material as the anode 151of the organic light emitting element 150, but is not limited thereto.Further, the data pad 163 may be made of the same material as the sourceelectrode 143 and the drain electrode 144 of the transistor 140, not onthe planarization layer 115, but on the inter-layer insulating layer114.

The connecting pad 162 may transmit a gate signal from a connecting line170, which functions as a gate line, to a plurality of subpixels SPX.The connecting pad 162 is connected with the gate pad 161 throughcontact holes formed at the planarization layer 115 and the inter-layerinsulating layer 114 and transmits a gate signal to the gate pad 161.The connecting pad 162 may be made of the same material as the data pad163, but is not limited thereto.

The organic light emitting elements 150 are components disposed tocorrespond to a plurality of subpixels SPX, respectively, and emit lighthaving a specific wavelength band. That is, the organic light emittingelement 150 may be a blue organic light emitting element that emits bluelight, a red organic light emitting element that emits red light, agreen organic light emitting element that emits green light, or a whiteorganic light emitting element that emits white light, but is notlimited thereto. When the organic light emitting element 150 is a whiteorganic light emitting element, the stretchable display device 100 mayfurther include a color filter.

The organic light emitting element 150 includes an anode 151, an organiclight emitting layer 152, and a cathode 153. In detail, the anode 151 isdisposed on the planarization layer 115. The anode 151 is an electrodeconfigured to supply holes to the organic light emitting layer 152. Theanode 151 may be made of a transparent conductive material with a highwork function. The transparent conductive material may include indiumtin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide(ITZO). The anode 151 may be made of the same material as the data pad163 and the connecting pad 162 disposed on the planarization layer 115,but is not limited thereto. Further, when the stretchable display device100 is implemented as a top emission type, the anode 151 may furtherinclude a reflective plate.

The anodes 151 are spaced apart from each other respectively forsubpixels SPX and electrically connected with the transistor 140 througha contact hole of the polarization layer 115. For example, although theanode 151 is electrically connected with the drain electrode 144 of thetransistor 140 in FIG. 3, it may be electrically connected with thesource electrode 143.

A bank 116 is formed on the anode 151, the data pad 163, the connectingpad 162, and the planarization layer 115. The bank 116 is a componentseparating adjacent subpixels SPX. The bank 116 is disposed to cover atleast partially both sides of adjacent anodes 151, thereby partiallyexposing the top of the anode 151. The bank 116 may suppress the problemthat an unexpected subpixel SPX emits light or colors are mixed by lightemitted in the lateral direction of the anode 151 due to concentrationof a current on the corner of the anode 151. The bank 116 may be made ofacrylic-based resin, benzocyclobutene (BCB)-based resin, or polyimide,but is not limited thereto.

The bank 116 has a contact hole for connecting the connecting line 170functioning as a data line and the data pad 163 and a contact hole forconnecting the connecting line 170 functioning as a gate line and theconnecting pad 162.

The organic light emitting layer 152 is disposed on the anode 151. Theorganic light emitting layer 152 is configured to emit light. Theorganic light emitting layer 152 may include a luminescent material, andthe luminescent material may include a phosphorous material or afluorescent material, but is not limited thereto.

The organic light emitting layer 152 may be composed of one lightemitting layer. Alternatively, the organic light emitting layer 152 mayhave a stacked structure in which a plurality of light emitting layersis stacked with a charge generation layer therebetween. The organiclight emitting layer 152 may further include at least one organic layerof a hole transporting layer, an electron transporting layer, a holeblocking layer, an electrode blocking layer, a hole injection layer, andan electron injection layer.

Referring to FIGS. 2 and 3, the cathode 153 is disposed on the organiclight emitting layer 152. The cathode 153 supplies electrons to theorganic light emitting layer 152. The cathode 153 may be made of indiumtin oxide (ITO)-based, indium zin oxide (IZO)-based, indium tin zincoxide (ITZO)-based, zinc oxide (ZnO)-based, or tin oxide (TO)-basedtransparent conductive oxides or an ytterbium (Yb) alloy. Alternatively,the cathode 153 may be made of a metal material.

The cathodes 153 may be formed by patterning to respectively overlap theplurality of island substrates 111. That is, the cathodes 153 may bedisposed not in the areas between the plurality of island substrates111, but only in the areas overlapping the plurality of islandsubstrates 111. Since the cathodes 153 are made of a transparentconductive oxide, a metal material, etc., when the cathodes 153 areformed even in the areas between the plurality of island substrates 111,the cathodes 153 may be damaged when the stretchable display device 100is stretched/contracted. Accordingly, the cathodes 153 may be formed torespectively correspond to the plurality of island substrates 111 on theplane. Referring to FIGS. 2 and 3, the cathodes 153 may be formed tohave an area not overlapping the area where a connection line 170 isdisposed, of the areas overlapping the plurality of island substrates111.

Unlike the conventional organic light emitting display devices, thecathodes 153 are formed by patterning to correspond to the plurality ofisland substrate 111 in the stretchable display device 100 according toan aspect of the present disclosure. Accordingly, each of the cathodes153 disposed on the plurality of island substrates 111 may beindependently supplied with low-potential power through the connectinglines 170.

Referring to FIGS. 2 and 3, an encapsulation layer 117 is disposed onthe organic light emitting element 150. The encapsulation layer 117 mayseal the organic light emitting element 150 by covering the organiclight emitting element 150 in contact with a portion of the top surfaceof the bank 116. Accordingly, the encapsulation layer 117 protects theorganic light emitting element 150 from water, air, or physical shockthat may permeate from the outside.

A plurality of encapsulation layers 117 respectively cover the cathodes153 patterned to respectively overlap the plurality of island substrate111 and may be formed on the plurality of island substrates 111,respectively. That is, each encapsulation layer 117 is disposed to coverone cathode 153 on one island substrate 111 and the plurality ofencapsulation layers 117 disposed on each of the plurality of islandsubstrates 111 may be spaced apart from each other.

The encapsulation layer 117 may be formed only in the areas overlappingthe plurality of island substrates 111. As described above, since theencapsulation layers 117 may be configured to include an inorganiclayer, they may be easily damaged, such as cracking, when thestretchable display device 100 is stretched. In particular, since theorganic light emitting element 150 is vulnerable to water or oxygen,when the encapsulation layer 117 is damaged, reliability of the organiclight emitting element 150 may be reduced. Therefore, since theencapsulation layer 117 is not formed in the areas between the pluralityof island substrates 111, damage to the encapsulation layer 117 may beminimized even though the stretchable display device 100 according to anaspect of the present disclosure is deformed, such as, bending orstretching.

Comparing the stretchable display device 100 according to an aspect ofthe present disclosure with common flexible organic light emittingdisplay devices of the related art, the stretchable display device 100according to an aspect of the present disclosure has a structure inwhich the plurality of island substrates 111 that are relatively rigidis spaced apart from each other and disposed on the lower substrate 110Athat is relatively soft or flexible. The cathodes 153 and theencapsulation layers 117 of the stretchable display device 100 aredisposed by patterning to correspond to the plurality of islandsubstrates 111, respectively. That is, the stretchable display device100 according to an aspect of the present disclosure may have astructure that enables the stretchable display device 100 to be moreeasily deformed when a user stretches or bends the stretchable displaydevice 100 and may have a structure that may minimize damage to thecomponents of the stretchable display device 100 when the stretchabledisplay device 100 is deformed.

<Connecting Lines Composed of Base Polymer & Conductive Particles>

The connecting lines 170 are lines that electrically connect the pads onthe plurality of island substrates 111. The connecting lines 170 includefirst connecting lines 171 and second connecting lines 172. The firstconnecting lines 171 are lines extending in an X-axis direction of theconnecting lines 170 and the second connecting lines 172 are linesextending in a Y-axis direction of the connecting lines 170. The X-axisdirection and Y-axis direction are positioned in a plane parallel to thedisplay surface and are referenced to the typical viewing orientation.

In the conventional organic light emitting display devices, variouslines such as a plurality of gate lines and a plurality of data linesare extended and disposed between a plurality of subpixels, and aplurality of subpixels is connected to one signal line. Accordingly, inthe conventional organic light emitting display devices, various linessuch as gate lines, data lines, high-potential power lines, andreference voltage lines extend continuously from one side to anotherside of the organic light emitting display device on the substrate.

However, in the stretchable display device 100 according to an aspect ofthe present disclosure, various lines such as gate lines, data lines,high-potential power lines, and reference voltage lines, which are madeof a metal material, are disposed only on the plurality of islandsubstrates 111. That is, in the stretchable display device 100 accordingto an aspect of the present disclosure, various lines made of a metalmaterial may be disposed only on the plurality of island substrates 111and may not be formed to be in contact with the lower substrate 110A.Accordingly, various lines may be patterned to correspond to theplurality of island substrates 111 and discontinuously disposed.

In the stretchable display device 100 according to an aspect of thepresent disclosure, the pads on two adjacent island substrates 111 maybe connected by a connecting line 170 to connect the discontinuouslines. That is, a connecting line 170 electrically connects the pads ontwo adjacent island substrates 111. Accordingly, the stretchable displaydevice 100 of the present disclosure includes a plurality of connectinglines 170 to electrically connect various lines such as gate lines, datalines, high-potential power lines, and reference voltage lines betweenthe plurality of island substrates 111. For example, gate lines may bedisposed on a plurality of island substrates 111 disposed adjacent toeach other in the X-axis direction, and the gate pad 161 may be disposedat both ends of the gate lines. Each of the plurality of gate pads 161on the plurality of island substrates 111 disposed adjacent to eachother in the X-axs direction may be connected to each other by aconnecting line 170 functioning as a gate line. Accordingly, the gatelines disposed on the plurality of island substrates 111 and theconnecting lines 170 disposed on the lower substrate 110A may functionas one gate line. Further, all various lines that may be included in thestretchable display device 100, such as the data lines, high-potentialpower lines, and reference voltage lines, also each may function as oneline by a connecting line 170, as described above.

Referring to FIG. 2, a first connecting line 171 may connectcorresponding pads on two island substrates 111 of the plurality ofisland substrates 111 disposed adjacent to each other and in a planeparallel to in the X-axial direction (referred to as X-axis parallel).The first connecting line 171 may function as a gate line or alow-potential power line, but is not limited thereto. For example, thefirst connecting line 171 may function as a gate line and mayelectrically connect the gate pads 161 on two X-axis parallel islandsubstrates 111 through a contact hole formed at the bank 116.Accordingly, as described above, the gate pads 161 on a plurality ofisland substrates 111 disposed parallel to the X-axs direction may beconnected by first connecting lines 171 that function as gate lines, andone gate signal may be transmitted.

Referring to FIG. 2, a second connecting line 172 may connectcorresponding pads on two island substrates 111 of the plurality ofisland substrates 111 disposed adjacent to each other and in a planeparallel to the Y-axis direction (referred to as Y-axis parallel). Thesecond connecting line 172 may function as a data line, a high-potentialpower line, or a reference voltage line, but is not limited thereto. Forexample, the second connecting line 172 may function as a data line andmay electrically connect the data pads 163 on two Y-axis parallel islandsubstrates 111 through a contact hole formed at the bank 116.Accordingly, as described above, the data pads 163 on a plurality ofisland substrates 111 disposed parallel to the Y-axis1 direction may beconnected by the plurality of second connecting lines 172 that functionsas data lines, and one data signal may be transmitted.

Referring to FIG. 2, the connecting line 170 includes a base polymer andconductive particles. In detail, the first connecting line 171 includesa base polymer 171 a and conductive particles 171 b and the secondconnecting line 172 includes a base polymer 172 a and conductiveparticles 172 b.

The base polymers 171 a and 172 a, similar to the lower substrate 110A,may be made of an insulating material that may be bent or stretched. Thebase polymers 171 a and 172 a, for example, may include styrenebutadiene styrene (SBS), etc., but are not limited thereto. Accordingly,when the stretchable display device 100 is bent or stretched, the basepolymers 171 a and 172 a may not be damaged.

The base polymers 171 a and 172 a are formed in a single layer on thelower substrate 110A between adjacent island substrates 111. In detail,the base polymers 171 a and 172 a are disposed in a single layer incontact with the lower substrate 110A in areas between most adjacentisland substrates 111 in the X-axis direction (171 a) and the Y-axisdirection (172 a) respectively. The base polymers 171 a and 172 a may beformed by coating a material for the base polymers 171 a and 172 a orapplying the material using a slit to the top surface of the lowersubstrate 110A and the island substrate 111.

<Straight Disposing of Conductive Particles>

Referring to FIG. 2, the conductive particles 171 b and 172 b mayconnect in a straight line the pads disposed on adjacent islandsubstrates 111 in the base polymers 171 a and 172 a. For this, in themanufacturing process, the conductive particles 171 b and 172 b areinjected in a straight line on the base polymers 171 a and 172 a, andaccordingly, the conductive particles 171 b and 172 b may be disposed ina straight line between the pads disposed respectively on the islandsubstrates 111 spaced apart from each other and adjacent to each otherover the base polymers 171 a and 172 a. Accordingly, the conductive pathformed by the conductive particles 171 b and 172 b also may be straight.

The first connecting line 171 includes the base polymer 171 a and theconductive particles 171 b. The base polymer 171 a may extend to the topsurface of the lower substrate 110A in contact with the top surface anda side of the bank 116 disposed on the island substrate 111, and sidesof the planarization layer 115, the inter-layer insulating layer 114,the buffer layer 112, and a plurality of island substrates 111.Accordingly, the base polymer 171 a may be in contact with the topsurface of the lower substrate 110A, a side of an adjacent islandsubstrate 111, and sides of the buffer layer 112, the gate insulatinglayer 113, the inter-layer insulating layer 114, the planarization layer115, and the bank 116 disposed on the adjacent island substrate 111. Thebase polymer 171 a may be in contact with the connecting pads 162disposed on adjacent island substrates 111, but is not limited thereto.

Referring to FIG. 4A and FIG. 4B, the conductive particles 171 b aredistributed and disposed in the base polymer 171 a and may form aconductive path electrically connecting the connecting pads 162respectively disposed on island substrates 111 adjacent to each other.Further, it is possible to form a conductive path by electricallyconnecting a gate pad 161 formed on the outermost island substrate 111of the plurality of island substrates 111 to a pad disposed in thenon-active area.

The conductive particles 171 b may be injected and distributed in thebase polymer 171 a by ink-printing, which uses conductive precursors,etc. on the top surface of the base polymer 171 a. When the conductiveparticles 171 b are injected into the base polymer 171 a, the conductiveparticles 171 b may permeate into an empty space of the base polymer 171a while the polymer swells several times. Thereafter, the connectingline 171 may be formed by dipping the base polymer 171 a with theconductive particles 171 b injected into a reducing material or byreducing the base polymer by vapor. The conductive particles 171 b mayinclude at least one of silver (Ag), gold (Au), and carbon, but are notlimited thereto.

Referring to FIG. 2, the base polymer 171 a may be disposed in one layerin the area between the plurality of island substrates 111. And, theconductive particles 171 b may be disposed while forming a plurality ofconductive paths on the base polymer 171 a disposed in one layer. Indetail, the base polymer 171 a may be formed to overlap all of aplurality of connecting pads 162 disposed on a side of one islandsubstrate 111. And, the conductive particles 171 b may be separatelyformed to respectively correspond to the plurality of connecting pads162 and may form a plurality of conductive paths electrically connectedrespectively with the connecting pads 162 overlapping the base polymer171 a. For example, as shown in FIG. 2, the conductive particles 171 bmay be injected to form four conductive paths on the top surface of thebase polymer 171 a disposed in one layer between the plurality of islandsubstrates 111.

<Density Gradient of Conductive Particles>

Referring to FIG. 4A, the conductive particles 171 b are distributed anddisposed with a density gradient in the base polymer 171 a. The densityof conductive particles 171 b increases towards the upper portion of abase polymer 171 a, so conductivity by conductive particles 171 b may bemaximum at the upper portion of a base polymer 171 a. In detail, each ofthe conductive particles 171 b may be in contact with each other at theupper portion of the base polymer 171 a, so a conductive path is formedby the conductive particles 171 b being in contact with each other, andaccordingly, an electrical signal may be transmitted.

Referring to FIG. 4A, the density of the conductive particles 171 b in apermeation area at the upper portion of the base polymer 171 a may behigh such that the conductive particles 171 b may form a conductivepath. The density of the conductive particles 171 b distributed in thepermeation area of the base polymer 171 a may be higher than the densityof the conductive particles 171 b in the other area of the base polymer171 a. Accordingly, a conductive path may be formed and an electricalsignal may be transmitted by the conductive particles 171 b distributedin the permeation area.

The thickness of the permeation area in which the conductive particles171 b are distributed with high density at the upper portion of the basepolymer 171 a may be changed in accordance with the time and intensityof injecting the conductive particles 171 b into the top surface of thebase polymer 171 a. When the time or intensity of injecting theconductive particles 171 b on the top surface of the base polymer 171 ais increased, the thickness of the permeation area may be increased.

Referring to FIG. 4B, the conductive particles 171 b distributed in thebase polymer 171 a in an area B in which the first connecting line 171and the connecting pad 162 are in contact may have substantially thesame density at the upper portion of the base polymer 171 a and at thelower portion of the base polymer 171 a. As described above, theconductive particles 171 b may be injected through the top surface ofthe base polymer 171 a and distributed at the upper portion of the basepolymer 171 a. At this time, for example, by increasing the time of theprocess of injecting the conductive particles 171 b, the conductiveparticles 171 b may be distributed with the same density at the upperportion and the lower portion of the base polymer 171 a, but are notlimited thereto.

Referring to FIG. 2, the second connecting line 172 includes the basepolymer 172 a and the conductive particles 172 b. The base polymer 172 amay extend to the top surface of the lower substrate 110A in contactwith the top surface and a side of the bank 116 disposed on the islandsubstrate 111, and sides of the planarization layer 115, the inter-layerinsulating layer 114, the buffer layer 112, and a plurality of islandsubstrates 111. Accordingly, the base polymer 172 a may be in contactwith the top surface of the lower substrate 110A, a side of an adjacentisland substrate 111, and sides of the buffer layer 112, the gateinsulating layer 113, the inter-layer insulating layer 114, theplanarization layer 115, and the bank 116 disposed on the adjacentisland substrate 111. The base polymer 172 a may be in contact with thedata pads 163 disposed on adjacent island substrates 111, but is notlimited thereto.

The conductive particles 172 b are disposed to be distributed in thebase polymer 172 a, thereby being able to form a conductive pathelectrically connecting the data pads 163 respectively disposed onadjacent island substrates 111. Further, the conductive particles mayform a conductive path by electrically connecting a data pad 163 formedon the outermost island substrate 111 of the plurality of islandsubstrate 111 to a pad disposed in the non-active area. The process inwhich the conductive particles 172 b are distributed in the base polymer172 a is the same as the process described about the first connectingline 171, so repeated description is omitted. Further, the processes ofdistributing the conductive particles 171 b and 172 b into the basepolymers 171 a and 172 a may be simultaneously performed.

Referring to FIG. 2, the base polymer 172 a may be disposed in one layerin the area between the plurality of adjacent island substrates 111.And, the conductive particles 172 b may be disposed while forming aplurality of conductive paths on the base polymer 172 a disposed in onelayer. In detail, the base polymer 172 a may be formed to overlap all ofa plurality of data pads 163 on a side on one island substrate 111. And,the conductive particles 172 b may form a plurality of conductive pathsrespectively electrically connected with the plurality of data pads 163overlapping the base polymer 172 a.

Referring to FIG. 3, the conductive particles 172 b are distributed anddisposed with a density gradient in the base polymer 172 a. The densityof conductive particles 172 b decreases as it goes from the upperportion of a base polymer 172 a toward the lower portion of the basepolymer 127 a, so conductivity by conductive particles 172 b may bemaximum at the upper portion of a base polymer 172 a. In detail, each ofthe conductive particles 172 b may be in contact with each other at theupper portion of the base polymer 172 a, so a conductive path is formedby the conductive particles 172 b being in contact with each other, andaccordingly, an electrical signal may be transmitted. The descriptionabout the density gradient and the conductive path of the conductiveparticles 172 b is the same as the description about the conductiveparticles 171 b, so repeated description is omitted.

Meanwhile, the conductive particles 172 b, unlike those shown in FIGS. 3to 4B, may be distributed and disposed without a density gradient in thebase polymer 172 a. The density of the conductive particles 172 bdisposed at the upper portion of the base polymer 172 a and the densityof the conductive particles 172 b disposed at the lower portion of thebase polymer 172 a may be the same. However, they are not limitedthereto.

Referring back to FIG. 3, the upper substrate 110B, the polarizing plate119, and the adhesive layer 118 are disposed on the encapsulation layer117 and the lower substrate 110A. The upper substrate 110B is asubstrate supporting various components disposed under the uppersubstrate 110B. The upper substrate 110B and the lower substrate 110Amay be bonded through the adhesive layer 118 disposed under the uppersubstrate 110B by applying pressure to the upper substrate 110B and thelower substrate 110A.

The polarizing plate 119 is disposed on the upper substrate 110B. Thepolarizing plate 119 may polarize light incident into the stretchabledisplay device 100 from the outside. Light incident and polarized in thestretchable display device 100 through the polarizing plate 119 may bereflected in the stretchable display device 100, so the phase of thelight may be changed. The light with the changed phase may not passthrough the polarizing plate 119. Accordingly, light incident in thestretchable display device 100 from the outside of the stretchabledisplay device 100 is not discharged back to the outside of thestretchable display device 100, so the external light reflection of thestretchable display device 100 may be reduced.

<Stretching Characteristic by Plurality of Island Substrates>

A stretchable display device needs an easy bending or stretchingcharacteristic, so there have been attempts to use substrates that havea flexible property due to a small modulus. However, when a flexiblematerial such as polydimethylsiloxane (PDMS) having a small modulus isused as a lower substrate that is disposed in the process ofmanufacturing display elements, there is a problem that the substrate isdamaged by high temperature, for example, temperature over 100° C. thatis generated in the process of forming transistors and the displayelements due to the characteristic that a material having a smallmodulus tends to be weak against heat.

Accordingly, display elements should preferably be formed on a substratemade of a material that can withstand high temperature, so damage to thesubstrate can be suppressed in the process of manufacturing the displayelements. Accordingly, there have been attempts to manufacture asubstrate using materials that can withstand high temperature, which isgenerated in the manufacturing process, such as polyimide (PI). However,the materials that can withstand high temperature do not have flexibleproperties due to large moduli, so substrates are not easily bent orstretched when the stretchable display devices are stretched.

Therefore, since the plurality of island substrates 111 that is rigidsubstrates is disposed only in the areas where transistors 140 ororganic light emitting elements 150 are disposed in the stretchabledisplay device 100 according to an aspect of the present disclosure,damage to the plurality of island substrates 111 due to high temperaturein the process of manufacturing the transistors 140 or the organic lightemitting elements 150 may be suppressed.

Further, the lower substrate 110A that is a flexible substrate may bedisposed under the plurality of island substrates 111 in the stretchabledisplay device 100 according to an aspect of the present disclosure.Accordingly, the other areas of the lower substrate 110A except theareas overlapping the plurality of island substrates 111 may be easilystretched or bent, so the stretchable display device 100 may beachieved. Further, it is possible to suppress the damage of thestretchable display device 100 by the transistors 140, the organic lightemitting elements 150, etc. disposed on the plurality of islandsubstrates 111 that is rigid substrates when the stretchable displaydevice 100 is bent or stretched.

<Effect of Connecting Lines>

Meanwhile, when a stretchable display device is bent or stretched, alower substrate that is a flexible substrate is deformed and islandsubstrates that are rigid substrates on which organic light emittingelements are disposed may not be deformed. In this case, if the linesconnecting the pads disposed on the plurality of island substrates arenot made of an easily bendable or stretchable material, the lines may bedamaged, such as cracking, due to deformation of the lower substrate.

In the stretchable display device 100 according to an aspect of thepresent disclosure, it is possible to electrically connect the padsdisposed on each of the plurality of island substrates 111, using theconnecting lines 170 including the base polymers 171 a and 172 a and theconductive particles 171 b and 172 b. The base polymer 171 a and 172 aare disposed in the areas between the plurality of island substrates 111and are soft or flexible to be able to easily deform. Accordingly, thestretchable display device 100 of an aspect of the present disclosurehas an effect that even though the stretchable display device 100 isdeformed such as bending or stretching, the areas between the pluralityof island substrates 111 on which the base polymers 171 a and 172 a aredisposed may be easily deformed.

Further, in the stretchable display device 100 of an aspect of thepresent disclosure, since the connecting lines 170 include theconductive particles 171 b and 172 b, damage such as cracking may not begenerated in the conductive path formed on the base polymers 171 a and172 a by the conductive particles 171 b and 172 b even by deformation ofthe base polymers 171 a and 172 a. For example, when the stretchabledisplay device 100 is deformed such as bending or stretching, the lowersubstrate 110A that is a flexible substrate may be deformed in the otherareas excepting the areas where the plurality of island substrates 111that is rigid substrates is disposed. At this time, the distance betweenthe plurality of conductive particles 171 b and 172 b disposed in somearea of the deforming lower substrate 110A may be changed. At this time,the density of the plurality of conductive particles 171 b and 172 bdisposed at the upper portion of the base polymers 171 a and 172 a andforming conductive paths may be maintained to be high such thatelectrical signals may be transmitted even though the distance betweenthe plurality of conductive particles 171 b and 172 b is increased.Accordingly, even if the base polymers 171 a and 172 a are bent orstretched, the conductive paths formed by the plurality of conductiveparticles 171 b and 172 b may still transmit electrical signals.Further, even though the stretchable display device 100 is deformed suchas bending or stretching, electrical signals may be transmitted betweenthe pads.

In the stretchable display device 100 according to an aspect of thepresent disclosure, the conductive particles 171 b and 172 b connectingeach pad disposed on the plurality of island substrates 111 adjacent toeach other make a shortest distance, that is, are distributed in astraight line in the base polymers 171 a and 172 a, so the stretchabledisplay device 100 may be implemented even though the connecting lines170 are not formed in a curved shape. The conductive particles 171 b and172 b of the connecting lines 170 form a conductive path by beingdistributed at the upper portion of the base polymer 171 a and 172 a.Further, when the stretchable display device 100 is deformed such asbending or stretching, the conductive paths formed by the conductiveparticles 171 b and 172 b may be bent or stretched. In this case, onlythe distance between the conductive particles 171 b and 172 b is changedand the conductive paths formed by the conductive particles 171 b and172 b may still transmit electrical signals.

Further, when the conductive particles 171 b and 172 b of the connectinglines 170 are distributed not in a straight line, but in curved shape,the force of deforming into a straight line may be generated in theconductive particles 171 b and 172 b distributed in the curved shape.Accordingly, in the stretchable display device 100 according to anaspect of the present disclosure, by distributing the conductiveparticles 171 b and 172 b of the connecting lines 170 in a straightline, it is possible to remove any force that may be generated bydistributing the conductive particles 171 b and 172 b in a curved shapeAccordingly, in the stretchable display device 100 according to anaspect of the present disclosure, it is possible to minimize deformationof the connecting lines 170, maintain the adhesive force between theconnecting lines 170 and other components, and minimize the space thatthe connecting lines 170 occupy.

<Connecting Lines for Compensating for Step>

FIG. 5 is a schematic cross-sectional view of one subpixel of astretchable display device according to another aspect of the presentdisclosure. A stretchable display device 500 shown in FIG. 5 issubstantially the same as the stretchable display device 100 shown inFIGS. 1 to 4B except for having a different connecting line 570 (571 and572), so repeated description is omitted.

Referring to FIG. 5, the top surface of base polymers 571 a and 572 a ofthe connecting line 570 is flat. In detail, the top surface of the basepolymers 571 a and 572 a of the connecting line 570 such as a gate lineand a data line may be higher than the top surface of the planarizationlayer 115 on a plurality of island substrates 111. Further, the topsurface of the base polymers 571 a and 572 a may be higher (further awayfrom lower substrate 110A) than the top surface of the bank 116 on theplurality of island substrates 111. Accordingly, the base polymer 571 aof a first connecting line 571 functioning as a gate line may be thesame in height at the top surface of the portion overlapping theplurality of island substrates 111 and the top surface of the areasdisposed between the plurality of island substrates 111. Accordingly,the top surface of the first connecting line 571 may be flat.

Accordingly, the base polymer 572 a of a second connecting line 572functioning as a data line may be the same in height at the top surfaceof the portion overlapping the plurality of island substrates 111 andthe top surface of the areas disposed between the plurality of islandsubstrates 111. Accordingly, the top surface of the second connectingline 572 may be flat.

Accordingly, the top surface of the conductive particles 571 b and 572 bdistributed at the upper portion of the base polymers 571 a and 572 amay be flat without a curve in a cross-sectional view.

A transistor 140, a planarization layer 115, an organic light emittingelement 150, a bank 116, an encapsulation layer 117, etc. are disposedon the plurality of island substrates 111 spaced and disposed on thelower substrate 110A. Accordingly, a step may exist between the topsurface of the bank 116 and the top surface of the lower substrate 110A.

At this time, if the top surface of the base polymers 571 a and 572 a isnot flat and a step exists on the top surface of the base polymers 571 aand 572 a by the step between the top surface of the bank 116 and thetop surface of the lower substrate 110A (as shown in FIG. 3), the basepolymers 571 a and 572 a themselves may be cut or broken by the step onthe top surface of the base polymers 571 a and 572 a. Further, when thestretchable display device 500 is bent or stretched, the base polymers571 a and 572 a may be cut or broken by the step on the top surface ofthe base polymers 571 a and 572 a. In this case, the electrical pathbetween the pads disposed on adjacent island substrates 111 is cut orbroken, so an electrical signal may not be transmitted and a percentagedefective of the stretchable display device 500 may increase.

Accordingly, the top surface of the base polymers 571 a and 572 a may beflat in the stretchable display device 500 according to another aspectof the present disclosure. Accordingly, in the base polymers 571 a and572 a, the step between the top surface of the elements disposed on theplurality of island substrates 111 and the top surface of the lowersubstrate 110A on which the plurality of island substrates 111 is notdisposed may be removed as shown in FIG. 5. Accordingly, a disconnectionphenomenon of the connecting lines 570 including the base polymers 571 aand 572 a and the conductive particles 571 b and 572 b due to a step maybe suppressed even though the stretchable display device 500 is bent orstretched.

Further, the top surface of the base polymers 571 a and 572 a is flat ina stretchable display device 500 according to another aspect of thepresent disclosure, so damage to the connecting lines 570 in themanufacturing process of the stretchable display device 500 may beminimized. In the manufacturing process of the stretchable displaydevice 500, various components including the connecting lines 570 areformed in a state in which the plurality of island substrates 111 isdisposed not on the lower substrate 110A, but on a glass substrate orsacrifice layer on a glass substrate. Thereafter, a sacrifice layerremoval process such as laser release is performed, and the bottomsurface of the plurality of island substrates 111 and the bottom surfaceof the base polymers 571 a and 572 a of the connecting lines 570 may beexposed. And, the lower substrate 110A may be bonded to the exposedbottom surface of the plurality of island substrates 111 and exposedbottom surface of the base polymers 571 a and 572 a.

In this case, in the process in which the sacrifice layer is removed,the base polymers 571 a and 572 a of the connecting lines 570 may bedamaged such as tearing of the base polymers 571 a and 572 a. Inparticular, when the base polymers 571 a and 572 a are formed with auniform thickness and a step exists on the top surface of the basepolymers 571 a and 572 a, the base polymers 571 a and 572 a may bedamaged or removed together in the sacrifice layer removal process. Inthis case, a problem may be generated with electrical signaltransmission between the pads disposed on the plurality of islandsubstrates 111 through the connecting line 570.

In the stretchable display device 500 according to another aspect of thepresent disclosure, the top surface of the base polymers 571 a and 572 ais formed flat, so the thickness of the base polymers 571 a and 572 a inthe areas between the plurality of island substrates 111 may beincreased. Accordingly, in the process in which the sacrifice layer isremoved, damage to the base polymers 571 a and 572 a and the conductivepaths formed by the conductive particles 571 b and 572 b distributed atthe upper portion of the base polymers may be suppressed. Accordingly,stability of electrical signal transmission of the stretchable displaydevice 500 may be increased.

<Base Polymer of Connecting Lines Covering Island Substrate>

FIG. 6 is a schematic cross-sectional view of one subpixel of astretchable display device according to another aspect of the presentdisclosure. The stretchable display device 600 of FIG. 6 issubstantially the same as the stretchable display device 500 of FIG. 5except that the connecting line 670 (671 and 672) further include anadditional base polymer 673, so repeated description is omitted.

Referring to FIG. 6, the connecting lines 670 may include a firstconnecting line 671, a second connecting line 672, and an additionalbase polymer 673. The first connecting line 671 and the secondconnecting line 672 are substantially the same as the first connectingline 571 and the second connecting line 572 of FIG. 5, respectively, sorepeated description is omitted.

The additional base polymer 673 of the connecting line 670 covers anencapsulation layer 117 disposed on a plurality of island substrates111. In detail, the additional base polymer 673 may cover all of aplanarization layer 115, a bank 116, an organic light emitting element150, and an encapsulation layer 117 on the plurality of islandsubstrates 111.

The base polymer 671 a of the first connecting line 671, the basepolymer 672 a of the second connecting line 672, and the additional basepolymer 673 may be made of one base polymer through the same process.That is, in the process of forming the base polymer 671 a of the firstconnecting line 671 and the base polymer 672 a of the second connectingline 672, the additional base polymer 673 may be simultaneously formedsuch that the base polymers 671 a and 672 a cover the componentsdisposed on the plurality of island substrates 111. Accordingly, the topsurface of the base polymers 671 a, 672 a and 673 that the connectingline 670 includes may be flat in the areas where the plurality of islandsubstrates 111 is disposed and the entire areas between the plurality ofisland substrates 111. However, the conductive particles 671 b and 672 bmay not be distributed in the additional base polymer 673.

In the stretchable display device 600 according to another aspect of thepresent disclosure, the base polymers 671 a, 672 a, 673 are disposed tocover all areas where the plurality of island substrates 111 is disposedand not disposed, and the top surface of the base polymers 671 a, 672 a,673 may be formed flat. Accordingly, a step by various componentsdisposed on the plurality of island substrates 111 may be removed.Accordingly, disconnection of the conductive path of the conductiveparticles 671 b and 672 b by a step may be suppressed.

Further, in the stretchable display device 600 according to anotheraspect of the present disclosure, the connecting line 670 includes theadditional base polymer 673 extending on the encapsulation layer 117 onthe plurality of island substrates 111. The additional base polymer 673covers various components such as the planarization layer 115, the bank116, the organic light emitting element 150, and the encapsulation layer117 disposed on the plurality of island substrates 111, so thecomponents of the stretchable display device 600 may be protected. Thebase polymers 671 a and 672 a and the additional base polymer 673 maycompletely seal various components disposed between the plurality ofisland substrates 111 and the additional base polymer 673. Accordingly,it is possible to protect various components from water, etc. thatpermeates from above the base polymers 671 a and 672 a and theadditional base polymer 673. Further, even if the stretchable displaydevice 600 is deformed such as bending or stretching, damage to thecomponents between the additional base polymer 673 and the plurality ofisland substrates 111 may be suppressed.

<Various Shapes of Base Polymer of Connecting Lines>

FIG. 7 is an enlarged plan view of a stretchable display deviceaccording to another aspect of the present disclosure. A stretchabledisplay device 700 shown in FIG. 7 is substantially the same as thestretchable display device 100 shown in FIGS. 1 to 4B except for havinga different connecting line 770, so repeated description is omitted.

Referring to FIG. 7, the connecting line 770 of the stretchable displaydevice 700 includes a base polymer 770 a and conductive particles 770 b.The base polymer 770 a is disposed in the entire area except the areaswhere a plurality of island substrates 111 is disposed. The base polymer770 a is disposed as a single layer in contact with the lower substrate110A, on the lower substrate 110A, that is, in the other areas exceptingthe areas overlapping the plurality of island substrates 111.Accordingly, the other areas except the areas overlapping the pluralityof island substrates 111 of the lower substrate 110A may be covered bythe base polymer 770 a. Further, as described above, the base polymer770 a may be in contact with pads of the plurality of island substrates111, so, a portion of the base polymer 770 a may be disposed to coverthe edge of the plurality of island substrates 111. The conductiveparticles 770 b are the same as the conductive particles 171 b and 172 bdescribed with reference to FIGS. 1 to 4B, repeated description isomitted.

In the stretchable display device 700 according to another aspect of thepresent disclosure, the base polymer 770 a is disposed as a single layerin the entire area excepting the areas where the plurality of islandsubstrates 111 is disposed on the lower substrate 110A, so the basepolymer 770 a may be more easily formed. That is, the base polymer 770 amay be formed in a way in which it is applied to all areas excepting theareas where the plurality of island substrates 111 is disposed of thelower substrate 110A, so a separate process for patterning the basepolymer 770 a may not be needed. Accordingly, in the stretchable displaydevice 700 according to another aspect of the present disclosure, themanufacturing process of the base polymer 770 a and the connecting line770 may be simplified, and the manufacturing costs and time may bereduced.

Further, in the stretchable display device 700 according to anotheraspect of the present disclosure, the base polymer 770 a is disposed asa single layer in the entire area excepting the areas where theplurality of island substrates 111 is disposed on the lower substrate110A, so it is possible to distribute force that is applied when thestretchable display device 700 is bent or stretched. For example, whenthe stretchable display device 700 is deformed such as bending orstretching, force such as tensile force may be applied to thestretchable display device 700, so the organic light emitting element150 of the stretchable display device 700 may be damaged. In thestretchable display device 700 according to another aspect of thepresent disclosure, the base polymer 770 a is disposed in the entirearea excepting the areas where the plurality of island substrates 111 isdisposed, so it is possible to distribute force by deformation of thestretchable display device 700. Accordingly, it is possible to protectseveral components of the stretchable display device 700.

FIG. 8 is an enlarged plan view of a stretchable display deviceaccording to another aspect of the present disclosure. A stretchabledisplay device 800 shown in FIG. 8 is substantially the same as thestretchable display device 100 shown in FIGS. 1 to 4B except for havinga different connecting line 870, so repeated description is omitted.

Referring to FIG. 8, the connecting line 870 of the stretchable displaydevice 800 includes a base polymer 870 a and conductive particles 870 b.The base polymer 870 a may be disposed only in areas overlapping theconductive particles 870 b on the lower substrate 110A. That is, thebase polymer 870 a may include a plurality of sub-base polymersoverlapping the conductive particles 870 b. The plurality of sub-basepolymers may be spaced apart from each other and disposed only in areasoverlapping conductive paths formed by the conductive particles.However, when the plurality of sub-base polymers and the areas where theconductive particles 870 b are distributed are the same in width,aligning may be difficult in the process of injecting the conductiveparticles 870 b. Accordingly, in consideration of a process error, asshown in FIG. 8, the width of the plurality of sub-base polymers of thebase polymer 870 a may be larger than the width of the areas where theconductive particles 870 b are distributed.

When conductive particles are injected to form a plurality of conductivepaths on a single base polymer, conductive particles supposed to formdifferent conductive paths may be unintentionally connected to eachother, so adjacent conductive paths may be connected to each other. Inthis case, two lines transmitting different signals are connected, so aproblem may be generated with signal transmission.

Accordingly, in the stretchable display device 800 according to anotheraspect of the present disclosure, the base polymer 870 a includes aplurality of sub-base polymers and the plurality of sub-base polymersmay be disposed only in the areas overlapping the conductive particles870 b or may be disposed in areas the same as or larger than the areaswhere the conductive particles 870 b are distributed. Accordingly, aplurality of conductive paths formed by the conductive particles 870 bmay be separated from each other by the plurality of sub-base polymers.Accordingly, each of the conductive paths formed by the conductiveparticles 870 b may not be connected to each other, and a problem maynot be generated with signal transmission of the stretchable displaydevice 800.

<Connecting Lines Configured by Metal Material>

FIG. 9 is an enlarged plan view of a stretchable display deviceaccording to another aspect of the present disclosure. FIG. 10 is across-sectional view schematically showing one subpixel of thestretchable display device of FIG. 9. A stretchable display device 900shown in FIGS. 9 and 10 is substantially the same as the stretchabledisplay device 100 shown in FIGS. 1 to 4B except for having a differentconnecting line 970 and further including a conductive reinforcingmember 980, so repeated description is omitted. Only encapsulationlayers 117 of various components disposed on island substrates 111, andconnecting lines 970 are shown in FIG. 9 for the convenience ofdescription.

Referring to FIG. 9, the connecting lines 970 of a stretchable displaydevice 900 have a curved shape. The connecting lines 970 electricallyconnect the pads disposed on adjacent island substrates 111 of aplurality of island substrates 111 and each extend not in a straightline, but in a curved shape between the pads. For example, as shown inFIGS. 9 and 10, a first connecting line 971 of the connecting lines 970may have a sine waveform. However, the shape of the first connectingline 971 is not limited to this shape and may have various shapes. Forexample, the first connecting line 971 may have various shapes, forexample, they may extend in a zigzag shape or a plurality ofdiamond-shaped connecting lines with the apexes not at the peak area,PA, connected (see FIG. 13 and corresponding description for furtherexplanation of peak area, PA). Moreover, the shape of the firstconnecting line may be any shape that allows deformation towards astraight line when stretched, twisted or otherwise distorted. Further,the second connecting line 972 may have the same shape as the firstconnecting line 971.

Referring to FIG. 10, a gate pad 961 is formed on a gate insulatinglayer 113 and a first connecting line 971 is formed on the gateinsulating layer 113 and the lower substrate 110A.

Referring to FIG. 10, the first connecting line 971 that can function asa gate line is connected with the gate pad 961 and extends from the topsurface of the gate insulating layer 113 to the top surface of the lowersubstrate 110A. Accordingly, the first connecting lines 971 mayelectrically connect the gate pads 961 respectively formed on adjacentisland substrates 111. The first connecting line 971 is in contact withthe lower substrate 110A between the plurality of island substrates 111except for the area overlapping the conductive reinforcing member 980.

The first connecting line 971 and the gate pad 961 may be made of thesame material as a gate electrode 141. Accordingly, the first connectingline 971 and the gate pad 961 may be simultaneously formed in the sameprocess as the gate electrode 141. Accordingly, the first connectingline 971 may be integrally formed by extending from the gate pad 961.However, the present disclosure is not limited thereto, and the gate pad961 and the first connecting line 971 may be made of differentmaterials, and may be disposed on different layers and electricallyconnected.

Referring to FIG. 10, a second connecting line 972 that can function asa data line is formed on an inter-layer insulating layer 114. The sourceelectrode 143 may extend outside an island substrate 111, may functionas a data pad, and may be electrically connected with the secondconnecting line 972. However, the present disclosure is not limitedthereto, and a separate data pad may be defined as extending from thesource electrode 143 or being electrically connected with the sourceelectrode 143.

Further, the second connecting line 972 is connected with the sourceelectrode 143 and extends from the top surface of an adjacent islandsubstrate 111 to the top surface of the lower substrate 110A.Accordingly, the second connecting line 972 may electrically connect thedata pad formed on each of adjacent island substrates 111. The secondconnecting line 972 is in contact with the lower substrate 110A betweenthe plurality of island substrates 111 except for the area overlappingthe conductive reinforcing member 980.

The second connecting line 972 may be made of the same material as adata pad, that is, the source electrode 143. Accordingly, the secondconnecting line 972, the source electrode 143, and the drain electrode144 may be simultaneously formed in the same process. Accordingly, thesecond connecting line 972 may be integrally formed by extending fromthe source electrode 143. However, the present disclosure is not limitedthereto, and the second connecting line 972 and the source electrode 143may be made of different materials, and may be disposed on differentlayers and electrically connected.

In the stretchable display device 900 according to another aspect of thepresent disclosure, connecting lines 970 electrically connecting padsformed on the plurality of island substrates 111, such as the firstconnecting line 971 and the second connecting line 972, may be made ofthe same material as at least one of a plurality of conductivecomponents 141, 143, 144, 151, 153 disposed on the plurality of islandsubstrates 111. For example, the first connecting line 971 may be madeof the same material as the gate electrode 141 and the second connectingline 972 may be made of the same material as the source electrode 143.However, the present disclosure is not limited thereto and theconnecting lines 970 may be made of the same material as (other than thegate electrode 141 and the source electrode 143), a drain electrode 144,the electrodes of an organic light emitting element 150 such as an anode151 and a cathode 153 of the organic light emitting element 150, orvarious lines included in the stretchable display device 900.Accordingly, the connecting lines 970 may be simultaneously formed inthe manufacturing process of conductive components 141, 143, 144, 151,153 disposed on the plurality of island substrates 111 and made of thesame material as the connecting lines 970 in the stretchable displaydevice 900 according to another aspect of the present disclosure.Therefore, there may not be a need for a separate manufacturing processfor forming the connecting lines 970.

<Conductive Reinforcing Member>

A conductive reinforcing member 980 is disposed under a portion of theconnecting line 970. The conductive reinforcing member 980 is acomponent that suppresses damage or disconnection of the connectinglines 970 when the stretchable display device 900 is repeatedlystretched, and that helps electrical signal transmission by being incontact with the connecting lines 970 even if the connecting lines 970are cut or broken.

The conductive reinforcing member 980 may be a conductive polymerincluding a base polymer and conductive particles distributed in thebase polymer. The conductive reinforcing member 980, which is aconductive polymer with conductive particles uniformly distributed in abase polymer, may have a flexible property because the base polymer hasstretching property. That is, the conductive reinforcing member 980 maybe a conductive flexible layer having both conductivity and flexibility.

The base polymer is a base layer in which conductive particles can bedistributed, and may include styrene butadiene styrene (SBS), but is notlimited thereto. Accordingly, the base polymer has stretching property,so when the stretchable display device 900 is bent or stretched, thebase polymer may not be damaged.

The conductive particles, which are particles having conductivity, mayinclude at least one of silver (Ag), gold (Au), and carbon.

The conductive particles may be uniformly distributed in the basepolymer. That is, the density of the conductive particles in theconductive reinforcing member 980 may be uniform. For example, theconductive reinforcing member may be formed in a way of putting a basepolymer in a separate container, uniformly distributing conductiveparticles in the base polymer by putting in and stirring the conductiveparticles, and then coating the base polymer in which the conductiveparticles are distributed on the lower substrate 110A, but is notlimited thereto.

The conductive reinforcing member 980 may be disposed adjacent to sidesof the plurality of island substrates 111 under the connecting lines 970such as the first connecting line 971 and the second connecting line972. For example, referring to FIG. 10, the conductive reinforcingmember 980 may be in contact with the bottom surface of the firstconnecting line 971 and the sides of the plurality of island substrates111. Further, the conductive reinforcing member 980 may be in contactwith a side of the buffer layer 112 and a side of the gate insulatinglayer 113, depending on the height of the conductive reinforcing member980. That is, the conductive reinforcing member 980 is disposed underthe first connecting line 971 in an area adjacent to the plurality ofisland substrates 111 of the first connecting line 971 and may be incontact with a side of at least some of the components disposed underthe gate pad 961.

<Effect of Connecting Line and Conductive Reinforcing Member>

When a connecting line is made of the same material as the conductivecomponents 141, 143, 144, 151, 153 disposed on a plurality of islandsubstrates, that is, a connecting line is made of a metal material, aflexible property of the connecting line may be low. In this case, whena stretchable display device is deformed such as bending or stretching,the connecting line may be damaged, for example, a crack is generated inthe connecting line having a low flexible property. Accordingly, aproblem may be generated with transmission of an electrical signalbetween pads on the plurality of island substrates.

Accordingly, in the stretchable display device 900 according to anotheraspect of the present disclosure, the connecting line 970 has a curvedshape, so damage to the connecting line 970 may be minimized even thoughthe stretchable display device 900 is deformed such as bending orstretching. Accordingly, in the stretchable display device 900 accordingto another aspect of the present disclosure, even though the connectingline 970 is made of a metal material, electrical signals may be stablytransmitted between the pads on the plurality of island substrates 111.

Further, when a plurality of island substrates is disposed on a lowersubstrate and connecting lines are formed on the lower substrate toelectrically connect pads of adjacent island substrates, a step mayexist on the connecting lines disposed on the plurality of islandsubstrates and the connecting lines disposed on the lower substrate bythe thickness of several components disposed on the plurality of islandsubstrates. In particular, the thickness of the plurality of islandsubstrates may be larger than the entire thickness of several componentsdisposed on the plurality of island substrates. For example, thethickness of the plurality of island substrates may be about 6 μm.Accordingly, when a stretchable display device is bent or stretched by astep caused by the components on the plurality of island substrates,there is a problem that the connecting lines may be damaged such asdisconnection of the connecting lines at the portion where a step of theconnecting lines exists, particularly, the boundary portion of theisland substrates.

Accordingly, in the stretchable display device 900 according to anotheraspect of the present disclosure, damage to the connecting lines 970 maybe suppressed by disposing the conductive reinforcing member 980 beingin contact with sides of the plurality of island substrates 111 andincluding a base polymer having flexible property, under the connectinglines 970. In detail, the conductive reinforcing member 980 includes abase polymer having a flexible property. And, the conductive reinforcingmember 980 is disposed under the connecting lines 970 in areas adjacentto the plurality of island substrates 111, so a step on the top surfaceof the connecting lines 970 may be attenuated (the corner of the stepmay be made smoother, in other words rounded), and accordingly, a rapidheight change of the connecting lines 970 may be reduced. Accordingly,even if the stretchable display device 900 is bent or stretched, damagethat may be generated in the connecting lines 970 may be minimized bystep attenuation of the conductive reinforcing member 980. Further, evenif the connecting lines 970 are damaged at the boundary portion of theisland substrates 111, the conductive reinforcing member 980 provides aconductive path, so signal transmission through the connecting lines 970may be stably provided.

Further, in the stretchable display device 900 according to anotheraspect of the present disclosure, the conductive reinforcing member 980disposed under the connecting lines 970 may reinforce the adhesive forcebetween the connecting lines 970 and the lower substrates 110A. When theconnecting line 970 made of a metal material is directly disposed on thelower substrate 110A, a phenomenon in which the connecting lines 970come off the lower substrate 110A may be generated due to a weakadhesive force between the lower substrate 110A and the connecting lines970. Accordingly, in the stretchable display device 900 according toanother aspect of the present disclosure, the conductive reinforcingmember 980 is disposed between the connecting lines 970 and the lowersubstrate 110A, so the adhesive force between the connecting lines 970and the lower substrate 110A may be reinforced, and the connecting lines970 coming off the lower substrate 110A may be suppressed.

<Conductive Reinforcing Member Made of Liquid Metal>

Meanwhile, the conductive reinforcing member 980 may include liquidmetal. The liquid metal means metal existing in a liquid state at roomtemperature. For example, the liquid metal may include at least one ofgallium, indium, natrium, lithium, and an alloy thereof, but is notlimited thereto. When a crack is generated in the connecting lines 970,the liquid metal may fill the crack of the connecting lines 970.Accordingly, in the stretchable display device 900 according to anotheraspect of the present disclosure, the conductive reinforcing member 980includes liquid metal, so disconnection of the connecting lines 970 maybe minimized by filling the crack with the liquid metal even though thestretchable display device 900 is deformed such as bending or stretchingand a crack is generated in the connecting lines. Further, the liquidmetal has conductivity, so the entire resistance in the connecting lines970 and the liquid metal may be reduced. Accordingly, there is an effectthat electrical signals may be more smoothly transmitted between thepads on the plurality of island substrates 111. Any conductivereinforcing member of any embodiment described herein may be made ofliquid metal.

<Conductive Reinforcing Member Over Connecting Line>

FIG. 11 is a schematic cross-sectional view of one subpixel of astretchable display device according to another aspect of the presentdisclosure. A stretchable display device 1100 shown in FIG. 11 issubstantially the same as the stretchable display device 900 shown inFIGS. 9 and 10 except that the positions where conductive reinforcingmember 1180 and a connecting line 1170 are disposed are different, sorepeated description is omitted.

Referring to FIG. 11, the conductive reinforcing member 1180 is disposedover a portion of the connecting line 1170. The conductive reinforcingmember 1180, which is a conductive polymer with conductive particlesdistributed in a base polymer, as described above, may be a conductiveflexible layer having both conductivity and flexibility.

The conductive reinforcing member 1180 may be disposed over theconnecting lines 1170, adjacent to sides of a plurality of islandsubstrates 111. In detail, the conductive reinforcing member 1180 may bedisposed adjacent to sides of the island substrates 111 with a firstconnecting line 1171 therebetween in contact with the top surface of thefirst connecting line 1171, which can function as a gate line, and notin contact with the sides of the island substrates 111. As describedabove, in the first connecting line 1171, a step may exist between areasoverlapping the plurality of island substrates 111 and areas notoverlapping the plurality of island substrates 111. For example, anisland substrate 111, a buffer layer 112, and a gate insulating layer113 are disposed under the first connecting line 1171 in the areasoverlapping the plurality of island substrates 111. Accordingly, a stepcorresponding to the entire thickness of the island substrate 111, thebuffer layer 112, and the gate insulating layer 113 may be generated inthe first connecting line 1171. The conductive reinforcing member 1180may be disposed on the first connecting line 1171 in the area adjacentto the plurality of island substrates 111, that is, the area where astep of the first connecting line 1171 is generated.

And, the conductive reinforcing member 1180 may be disposed in areasadjacent to sides of the island substrates 111 with a second connectingline 1172 therebetween in contact with the second connecting line 1172,which can function as a data line, and not in contact with the sides ofthe island substrates 111. As described above, in the second connectingline 1172, a step may exist between areas overlapping the plurality ofisland substrates 111 and areas not overlapping the plurality of islandsubstrates 111. For example, an island substrate 111, a buffer layer112, a gate insulating layer 113, and an inter-layer insulating layer114 are disposed under the second connecting line 1172 in the areasoverlapping the plurality of island substrates 111. Accordingly, a stepcorresponding to the entire thickness of the island substrate 111, thebuffer layer 112, the gate insulating layer 113, and the inter-layerinsulating layer 114 may be generated in the second connecting line1172. The conductive reinforcing member 1180 may be disposed on thesecond connecting line 1172 in the area adjacent to the plurality ofisland substrates 111, that is, the area where a step of the secondconnecting line 1172 is generated.

Accordingly, in the stretchable display device 1100 according to anotheraspect of the present disclosure, damage to the connecting lines 1170may be suppressed by including the conductive reinforcing member 1180disposed adjacent to sides of the plurality of island substrates 111over the connecting lines 1170. In detail, the conductive reinforcingmember 1180 includes a base polymer having a flexible property. And, astep may be generated on the top surface of the connecting lines 1170 bythe entire thickness of a plurality of layers disposed under theconnecting lines 1170 in the areas overlapping the plurality of islandsubstrates 111. When the stretchable display device 1100 is deformedsuch as bending or stretching, damage such as generation of crack ordisconnection of the connecting lines 1170 may be generated. Theconductive reinforcing member 1180 is disposed over the connecting lines1170 in the areas adjacent to the plurality of island substrates 111, soeven if the connecting lines 1170 is cracked or disconnected, anelectrical signal may be transmitted through the conductive reinforcingmember 1180 being in contact with the top surface of the connectinglines 1170. Accordingly, the electrical signal transmission of thestretchable display device 1100 may be stably made.

Further, in the stretchable display device 1100 according to anotheraspect of the present disclosure, the conductive reinforcing member 1180is disposed over the connecting lines 1170, so the process of formingthe conductive reinforcing member 1180 may be more easily performed. Indetail, the conductive reinforcing member 1180 may be formed on theconnecting lines 1170 before the upper substrate 110B and the polarizingplate 119 are bonded by the adhesive layer 118 after the connectinglines 1170 and various components on the plurality of island substrates111 are all formed. Accordingly, in the stretchable display device 1100according to another aspect of the present disclosure, there is no needfor forming the conductive reinforcing member 1180 during themanufacturing process of the transistor 140 or the organic lightemitting element 150. Therefore, the manufacturing process of theconductive reinforcing member 1180 may be more easily made, and themanufacturing time or manufacturing costs may be minimized.

<Conductive Reinforcing Member Between Plurality of Connecting Lines>

FIG. 12 is a schematic cross-sectional view of one subpixel of astretchable display device according to another aspect of the presentdisclosure. A stretchable display device 1200 shown in FIG. 12 issubstantially the same as the stretchable display device 1100 shown inFIG. 11 except for having different connecting lines 1270 and conductivereinforcing member 1280, so repeated description is omitted.

Referring to FIG. 12, a first connecting line 1271 of the stretchabledisplay device 1200 includes a first sub-connecting line 1271 a and asecond sub-connecting line 1271 b. In detail, a first gate pad 1161 andthe first sub-connecting line 1271 a are disposed on a gate insulatinglayer 113. The first gate pad 1161 and the first sub-connecting line1271 a may be made of the same material as a gate electrode 141.Accordingly, the gate electrode 141, the first gate pad 1161, and thefirst sub-connecting line 1271 a may be simultaneously formed.

The first sub-connecting line 1271 a is connected with the first gatepad 1161 and extends onto the lower substrate 110A from the top surfaceof the gate insulating layer 113. Accordingly, the first sub-connectinglines 1271 a may electrically connect the first gate pads 1161 formed onadjacent island substrates 111. The first sub-connecting line 1271 a maybe in contact with the lower substrate 110A between the plurality ofisland substrates 111.

The conductive reinforcing member 1280 is disposed on the firstsub-connecting line 1271 a in areas adjacent to sides of the pluralityof island substrates 111 between the plurality of island substrates 111.An island substrate 111, a buffer layer 112, and a gate insulating layer113 are disposed under the first sub-connecting line 1271 a in the areasoverlapping the plurality of island substrates 111. Accordingly, a stepcorresponding to the entire thickness of the island substrate 111, thebuffer layer 112, and the gate insulating layer 113 may be generated inthe first sub-connecting line 1271 a. The conductive reinforcing member1280 may be disposed on the first sub-connecting line 1271 a in the areaadjacent to the plurality of island substrates 111, that is, the areawhere a step of the first sub-connecting line 1271 a is generated.

An inter-layer insulating layer 114 is disposed on the first gate pad1161 and the first sub-connecting line 1271 a. Further, a second gatepad 1162 and the second sub-connecting line 1271 b are disposed on theinter-layer insulating layer 114. The second gate pad 1162 iselectrically connected with the first gate pad 1161 through a contacthole formed in the inter-layer insulating layer 114. The second gate pad1162 and the second sub-connecting line 1271 b may be made of the samematerial, and for example, may be made of the same material as thesource electrode 143 and the drain electrode 144. Accordingly, thesecond gate pad 1162 and the second sub-connecting line 1271 b may beformed simultaneously with the source electrode 143 and the drainelectrode 144.

The second sub-connecting line 1271 b is connected with the second gatepad 1162 and extends onto the conductive reinforcing member 1280 fromthe top surface of the inter-layer insulating layer 114. And the secondsub-connecting line 1271 b extends onto the first sub-connecting line1271 a from the top surface of the conductive reinforcing member 1280.Accordingly, conductive reinforcing member 1280 is disposed over thefirst sub-connecting line 1271 a and under the second sub-connectingline 1271 b, and is disposed between the first sub-connecting line 1271a and the second sub-connecting line 1271 b. Accordingly, the topsurface of the first sub-connecting line 1271 a and the bottom surfaceof the conductive reinforcing member 1280 are in contact, and the bottomsurface of the second sub-connecting line 1271 b and the top surface ofthe conductive reinforcing member 1280 are in contact.

In the stretchable display device 1200 according to another aspect ofthe present disclosure, the first connecting line 1271 includes thefirst sub-connecting line 1271 a and the second sub-connecting line 1271b, and the conductive reinforcing member 1280 is disposed between thefirst sub-connecting line 1271 a and the second sub-connecting line 1271b. As described above, a step may be generated between the portion ofthe first connecting line 1271 overlapping the plurality of islandsubstrates 111 and the other portion not overlapping the plurality ofisland substrates 111. Accordingly, when the stretchable display device1200 is deformed such as bending or stretching, damage such as crackingor disconnection may be generated in the first connecting line 1271. Inthis case, in the stretchable display device 1200 according to anotheraspect of the present disclosure, the conductive reinforcing member 1280is disposed on the first sub-connecting line 1271 a, so even if thefirst sub-connecting line 1271 a is cracked or disconnected, electricalsignals may be transmitted by the conductive reinforcing member 1280.Further, a step of the second sub-connecting line 1271 b may becompensated or reduced by the conductive reinforcing member 1280, sodamage such as cracking or disconnection of the second sub-connectingline 1271 b may be suppressed.

Further, in the stretchable display device 1200 according to anotheraspect of the present disclosure, the conductive reinforcing member 1280is disposed between the first sub-connecting line 1271 a and the secondsub-connecting line 1271 b. Further, the first sub-connecting line 1271a, the second sub-connecting line 1271 b, and the conductive reinforcingmember 1280 are electrically connected. Accordingly, the entireresistance of the first sub-connecting line 1271 a, the secondsub-connecting line 1271 b, and the conductive reinforcing member 1280may be reduced, so the electrical signal transmission of the stretchabledisplay device 1200 may be more stably made.

In some aspects, the second connecting line 1172, as the firstconnecting line 1271, also may include a first sub-connecting line and asecond sub-connecting line. In this case, one of the firstsub-connecting line and the second sub-connecting line may be a lineconnected with the source electrode 143 and the other one may be made ofthe same material as the conductive component disposed under the sourceelectrode 143, for example, the same material as the gate electrode 142,or may be made of the same material as the conductive component disposedover the source electrode 143, for example, the same material as theanode 151. And, the conductive reinforcing member 1180 may be disposedbetween the first sub-connecting line and the second sub-connecting lineof the second connecting line 1172.

<Conductive Reinforcing Member Disposed in Peak Area of Connecting Line>

FIG. 13 is an enlarged plan view of a stretchable display deviceaccording to another aspect of the present disclosure. FIG. 14A and FIG.14B are cross-sectional views taken along line XIV-XIV′ of FIG. 13. Astretchable display device 1300 shown in FIGS. 13 to 14B issubstantially the same as the stretchable display device 900 shown inFIGS. 9 and 10 except for having different connecting lines 1370 and aconductive reinforcing member 1380, so repeated description is omitted.Only encapsulation layers 117 of various components disposed on islandsubstrates 111, and connecting lines 1370 are shown in FIG. 13 for theconvenience of description.

Referring to FIGS. 13 to 14B, a conductive reinforcing member 1380 isdisposed in a peak area PA of a connecting line 1370. The peak area PAof the connecting line 1370 means an area where the amplitude of thecurved connecting line 1370 is largest. For example, as shown in FIG.13, when the connecting lines 1370 have a sine waveform, the point wherethe amplitude of the connecting lines 1370 is largest may be defined asa peak area PA. A corresponding PA is also shown in FIG. 9. When theconnecting lines 1370 have another shape such as a zigzag or diamondshape, the corresponding point where the zigzag or diamond changesdirection may be defined as a peak area PA as would be understood. Whenthe stretchable display device 1300 is deformed such as bending orstretching, stress may concentrate on the peak area PA of the connectinglines 1370, as compared with other areas of the connecting lines 1370.

At this time, the conductive reinforcing member 1380 may be disposed atthe inner edge or inside of the peak area PA of the connecting lines1370. The inner edge of the peak area PA of the connecting lines 1370may mean an area where a radius of curvature is relatively small in thepeak area PA of the connecting lines 1370 and the outer edge of the peakarea PA may mean an area where the radius of curvature is relativelylarge in the peak area PA of the connecting lines 1370.

In general, when a line has a curved shape, an area with a small radiusof curvature may receive larger stress than an area with a large radiusof curvature. Accordingly, when the stretchable display device 1300 isdeformed such as bending or stretching, the inner edge of the peak areaPA of the connecting lines 1370 may be an area where stress isconcentrated more than the outer edge.

Accordingly, in the stretchable display device 1300 according to anotheraspect of the present disclosure, as shown in FIG. 14A, the conductivereinforcing member 1380 may be disposed under the connecting line 1370at the inner edge of the peak area PA of the connecting line 1370. Theconductive reinforcing member 1380 may be disposed in an areaoverlapping the inner edge of the peak area PA of the connecting line1370, and may be in contact with the bottom surface of the connectingline 1370 under the connecting line 1370.

Further, in the stretchable display device 1300 according to anotheraspect of the present disclosure, as shown in FIG. 14B, the conductivereinforcing member 1380 may be disposed over the connecting line 1370 atthe inner edge of the peak area PA of the connecting line 1370. Theconductive reinforcing member 1380 may be disposed in an areaoverlapping the inner edge of the peak area PA of the connecting line1370, and may be in contact with the top surface of the connecting line1370 over the connecting line 1370.

In the stretchable display device 1300 according to another aspect ofthe present disclosure, the conductive reinforcing member 1380 may bedisposed in the peak area PA of the connecting line 1370, andparticularly, may be disposed at the inner edge of the peak area PA. Indetail, the peak area PA of the connecting line 1370 is an area withlarge amplitude in comparison to the other area of the connecting line1370, so the peak area PA of the connecting line 1370 may be an areawhere stress applied to the connecting line 1370 is concentrated.Further, the radius of curvature of the inner edge of the peak area PAof the connecting line 1370 may be smaller than the radius of curvatureof the outer edge. Accordingly, stress applied to the connecting line1370 may be more concentrated at the inner edge of the peak area PA.Accordingly, when the stretchable display device 1300 is deformed suchas bending or stretching, damage such as a crack or disconnection may beeasily generated in the peak area PA of the connecting lines 1370,particularly, at the inner edge of the peak area PA in comparison toother areas. At this time, the conductive reinforcing member 1380 may bedisposed in an area overlapping the peak area PA of the connecting line1370, particularly, may be disposed over or under the connecting line1370 in contact with the connecting line 1370 in an area overlapping theinner edge. Accordingly, a crack or damage that is generated in theconnecting line 1370 may be reduced by the conductive reinforcing member1380. Further, even if damage is generated in the peak area PA of theconnecting lines 1370 or at the inner edge of the peak area PA, theconductive reinforcing member 1380 may suppress blocking of anelectrical signal, so transmission of electrical signals in thestretchable display device 1300 may be more stably performed. Any shapeof connecting line in any embodiment having a peak area PA may have aconductive reinforcing member disposed either under, over, at an inneredge or at an outer edge, or any combination thereof, in a peak area ofthe connecting line as described.

<Stretchable Display Device Including Micro LED>

FIG. 15 is a schematic cross-sectional view showing one subpixel of astretchable display device according to another aspect of the presentdisclosure. A stretchable display device 1500 shown in FIG. 15 issubstantially the same as the stretchable display device 100 shown inFIGS. 1 to 4B except for including a different LED 1550, so repeateddescription is omitted.

Referring to FIG. 15, a common line CL is disposed on the gateinsulating layer 113. The common line CL is a line applying a commonvoltage to a plurality of subpixels SPX. The common line CL may be madeof the same material as the source electrode 143 and the drain electrode144 of the transistor 140, but is not limited thereto.

A reflective layer 1583 is disposed on the inter-layer insulating layer114. The reflective layer 1583 is a layer for discharging light emittedin the direction of the lower substrate 110A from the LED 1550 to theoutside the stretchable display device 1500 by reflecting the lightupward towards a user of the stretchable display device 1500. Thereflective layer 1583 may be made of a metal material having highreflectance.

An adhesive layer 1517 is disposed on the reflective layer 1583 to coverthe reflective layer 1583. The adhesive layer 1517, which is a layer forbonding the LED 1550 on the reflective layer 1583, may insulate thereflective layer 1583 made of a metal material and the LED 1550. Theadhesive layer 1517 may be made of a thermosetting material or aphotocuring material, but is not limited thereto. Although the adhesivelayer 1517 covers only the reflective layer 1583 in FIG. 15, theposition of the adhesive layer 1517 is not limited thereto.

The LED 1550 is disposed on the adhesive layer 1517. The LED 1550overlaps the reflective layer 1583. The LED 1550 includes an n-typelayer 1551, an active layer 1552, a p-type layer 1553, an n-electrode1555, and a p-electrode 1554. The LED 1550 is described as a lateral LED1550 hereafter, but the structure of the LED 1550 is not limitedthereto, and may be, for example, a vertical type LED or a flip-chipLED.

In detail, the n-type layer 1551 of the LED 1550 overlaps the reflectivelayer 1583 on the adhesive layer 1517. The n-type layer 1551 may beformed by injecting an n-type impurity into gallium nitride. The activelayer 1552 is disposed on the n-type layer 1551. The active layer 1552,which is a light emitting layer that emits light in the LED 1550, may bemade of a nitride semiconductor, for example, indium gallium nitride.The p-type layer 1553 is disposed on the active layer 1552. The p-typelayer 1553 may be formed by injecting a p-type impurity into galliumnitride. However, the materials composing the n-type layer 1551, theactive layer 1552, and the p-type layer 1553 are not limited thereto.

The p-electrode 1554 is disposed on the p-type layer 1553 of the LED1550. The n-electrode 1555 is disposed on the n-type layer 1551 of theLED 1550. The n-electrode 1555 is spaced and disposed apart from thep-electrode 1554. In detail, the LED 1550 may be manufactured bysequentially stacking the n-type layer 1551, the active layer 1552, andthe p-type layer 1553, etching a predetermined portion of the activelayer 1552 and the p-type layer 1553, and then forming the n-electrode1555 and the p-electrode 1554. The predetermined portion is a space forspacing the n-electrode 1555 and the p-electrode 1554 and thepredetermined portion may be etched to expose a portion of the n-typelayer 1551. In other words, the surface of the LED 1550 where then-electrode 1555 and the p-electrode 1554 are disposed is not aplanarized surface and may have different height levels. Accordingly,the p-electrode 1554 is disposed on the p-type layer 1553, then-electrode 1555 is disposed on the n-type layer 1551, and thep-electrode 1554 and the n-electrode 1555 are spaced and disposed apartfrom each other at different height levels. Therefore, the n-electrode1555 may be disposed closer to the reflective layer 1583 than thep-electrode 1554. The n-electrode 1555 and p-electrode 1554 may be madeof a conductive material, for example, a transparent conductive oxide.Alternatively, the n-electrode 1555 and p-electrode 1554 may be made ofthe same material, but are not limited thereto.

A planarization layer 115 is disposed on the inter-layer insulatinglayer 114 and the adhesive layer 1517. The planarization layer 115 is alayer that planarizes the top surface of the transistor 140. Theplanarization layer 115 may be disposed in an area excepting the areawhere the LED 1550 is disposed while planarizing the top surface of theplanarization layer 115. The planarization layer 115 may be composed oftwo or more layers.

A first electrode 1581 and a second electrode 1582 are disposed on theplanarization layer 115. The first electrode 1581 is an electrode thatelectrically connects the transistor 140 and the LED 1550. The firstelectrode 1581 is connected with the p-electrode 1554 of the LED 1550through a contact hole formed at the planarization layer 115. The firstelectrode 1581 is connected with the drain electrode 144 of thetransistor 140 through contact holes formed at the planarization layer115. However, the first electrode 1581 is not limited thereto and may beconnected with the source electrode 143 of the transistor 140, dependingon the type of the transistor 140. The p-electrode 1554 of the LED 1550and the drain electrode 144 of the transistor 140 may be electricallyconnected by the first electrode 1581.

The second electrode 1582 is an electrode that electrically connects theLED 1550 and the common line CL. In detail, the second electrode 1582 isconnected with the common line CL through contact holes formed at theplanarization layer 115 and the inter-layer insulating layer 114 and isconnected with the n-electrode 1555 of the LED 1550 through a contacthole formed at the planarization layer 115. Accordingly, the common lineCL and the n-electrode 1555 of the LED 1550 are electrically connected.

When the stretchable display device 1500 is turned on, voltages havingdifferent levels may be supplied respectively to the drain electrode 144of the transistor 140 and the common line CL. The voltage that isapplied to the drain electrode 144 of the transistor 140 may be appliedto the first electrode 1581 and a common voltage may be applied to thesecond electrode 1582. Voltages having different levels may be appliedto the p-electrode 1554 and the n-electrode 1555 through the firstelectrode 1581 and the second electrode 1582, so the LED 1550 may emitlight.

Although the transistor 140 is electrically connected with thep-electrode 1554 and the common line CL is electrically connected withthe n-electrode 1555 in the description referring to FIG. 15, they arenot limited thereto. That is, the transistor 140 may be electricallyconnected with the n-electrode 1555 and the common line CL may beelectrically connected with the p-electrode 1554.

A bank 116 is disposed on the planarization layer 115, the firstelectrode 1581, the second electrode 1582, the data pad 163, and theconnecting pad 162. The bank 116 is disposed to overlap an end of thereflective layer 1583 and a portion of the reflective layer 1583 notoverlapping the bank 116 may be defined as a light emitting area. Thebank 116 may be made of an organic insulating material and may be madeof the same material as the planarization layer 115. The bank 116 may beconfigured to include a black material to suppress mixing of colors dueto light emitted from the LED 1550 and transmitted to an adjacentsubpixel SPX.

The stretchable display device 1500 according to another aspect of thepresent disclosure includes the LED 1550. Since the LED 1550 is made ofnot an organic material, but an inorganic material, reliability is high,so the lifespan is longer than that of a liquid crystal display elementor an organic light emitting element. The LED 1550 is quickly turned on,consumes a small amount of power, has high stability because it has highshock-resistance, and may display high-luminance images because it hashigh emission efficiency. Accordingly, the LED 1550 is an element thatis suitable to be applied even to very large screens. In particular,since the LED 1550 is made of not an organic material, but an inorganicmaterial, an encapsulation layer that is required when an organic lightemitting element is used may not be used. Accordingly, the encapsulationlayer that may be easily damaged, such as cracking, when the stretchabledisplay device 1500 is stretched may be omitted. Accordingly, it ispossible not to use an encapsulation layer that may be damaged when thestretchable display device 1500 according to another aspect of thepresent disclosure is deformed such as bending or stretching, by usingthe LED 1550 as a display element in the stretchable display device1500. Further, since the LED 1550 is made of not an organic material,but an inorganic material, the display elements of the stretchabledisplay device 1500 according to another aspect of the presentdisclosure may be protected from water or oxygen and their reliabilitymay be high.

The exemplary aspects of the present disclosure can also be described asfollows:

According to an aspect of the present disclosure, a stretchable displaydevice comprises a plurality of island substrates on which a pluralityof pixels is defined and that is spaced apart from each other; a lowersubstrate disposed under the plurality of island substrates; connectinglines that electrically connect pads disposed on adjacent islandsubstrates of the plurality of island substrates, and have a curvedshape; and conductive reinforcing members disposed to be in contact withsome areas of the connecting lines.

The stretchable display device may further comprise a plurality ofconductive components respectively disposed on the plurality of islandsubstrates, wherein the connecting lines may be made of the samematerial as at least one of the plurality of conductive components.

The conductive reinforcing members may include a base polymer and aconductive polymer including conductive particles distributed in thebase polymer, or liquid metal.

The conductive reinforcing members may be disposed to be adjacent tosides of the plurality of island substrates.

The conductive reinforcing members may be disposed in peak areas of theconnecting lines.

The conductive reinforcing members may be disposed at inner edges of thepeak areas of the connecting lines.

The conductive reinforcing members may be disposed to be in contact withthe top surface or the bottom surface of the connecting lines.

The connecting lines may include a first sub-connecting line and asecond sub-connecting line disposed on the first sub-connecting line,and the conductive reinforcing members may be disposed between the firstsub-connecting line and the second sub-connecting line.

The connecting lines may be in contact with the lower substrate.

The stretchable display device may further comprise an adhesive layerdisposed to cover the connecting lines; and an upper substrate disposedon the adhesive layer and disposed to overlap the lower substrate.

The curved shape may include a zigzag shape, a sine waveform, or adiamond shape.

The stretchable display device may further comprise a plurality ofdisplay elements disposed on the plurality of island substrates, whereinthe plurality of display elements may be inorganic light emittingelements or organic light emitting elements.

According to another aspect of the present disclosure, a stretchabledisplay device comprises a lower flexible substrate; a plurality ofrigid substrates that is disposed on the lower flexible substrate, onwhich a plurality of pixels is defined, and that is spaced apart fromeach other; connecting lines that electrically connect pads disposedbetween adjacent rigid substrates of the plurality of rigid substrates,and are made of the same material as conductive components disposed onthe plurality of rigid substrates; and conductive flexible layersdisposed on the top surface or the bottom surface of the connectinglines.

The conductive components may be made of the same material as at leastone of a gate electrode, a source electrode, and a drain electrode of athin film transistor, a line, and an electrode of a display element.

The conductive flexible layers may include a base polymer and conductiveparticles distributed in the base polymer, or liquid metal.

The conductive flexible layers may be disposed to be in contact withsides of the plurality of rigid substrates or such that the connectinglines exist between the conductive flexible layers and the plurality ofrigid substrates.

The conductive flexible layers may be disposed to overlap an area withthe largest amplitude of the connecting lines.

The conductive flexible layers may be disposed inside the area with thelargest amplitude.

The connecting lines may include a first sub-connecting line and asecond sub-connecting line disposed on the first sub-connecting line,and the conductive flexible layers may be disposed between the firstsub-connecting line and the second sub-connecting line.

According to an aspect of the present disclosure, a display structurecomprises a first flexible substrate having a first modulus ofelasticity; a plurality of second substrates positioned on the firstflexible substrate and spaced apart from each other, each of the secondsubstrates being rigid and having a second modulus of elasticity that isgreater than first modulus of elasticity; at least one semiconductortransistor positioned on each of the second substrates of the plurality;and electrically conductive lines extending between respective ones ofthe second substrates, each of the electrically conductive linesconfigured to be stretched while remaining electrically conductive.

Each of the second substrates of the plurality may have a light emittingelement positioned thereon.

At least one of the electrically conductive lines extending betweenrespective ones of the second substrates may be a data line thatprovides a data signal to the light emitting element on the secondsubstrate.

The second modulus of elasticity may be more than one thousand timesgreater than the first modulus of elasticity.

The electrically conductive lines may have a flexible, twisty, wavyshape.

The electrically conductive lines may have a stretchable diamond shape.

At least one of the electrically conductive lines extending betweenrespective ones of the second substrates may be a gate line for the atleast one transistor.

According to an aspect of the present disclosure, a method of using astretchable display comprises stretching a first substrate having afirst modulus of elasticity a first distance; maintaining as rigid andunstretched a plurality of second substrates that are positioned on thefirst substrate positioned a first distance away from each other, eachof the second substrates having a second modulus of elasticity that isgreater that the first modulus of elasticity, each of the secondsubstrates of the plurality having at least one semiconductor transistorthereon; moving the respective second substrates a second distant fromeach other that is greater than the first distance during thestretching; and maintaining an electrical connection by a stretchableconductive line between respective ones of the plurality of secondsubstrates prior to and after the stretching.

The plurality of second substrates each may include an organic lightemitting diode and further including the step of: transmitting a lightemission data signal to the organic light emitting diodes during thestretching.

The method may further include terminating the stretching; and returningthe first substrate to the unstretched shape after the stretching.

According to another aspect of the present disclosure, a method ofmaking a stretchable display panel comprises providing a first flexiblesubstrate having a first modulus of elasticity; forming respectivesemiconductor transistor circuits on a plurality of second, rigidsubstrates, each of the second, rigid substrates having a second modulusof elasticity that is greater than the modulus of elasticity of thefirst flexible substrate, placing each of the plurality of second, rigidsubstrates on the first substrate spaced a selected distance apart fromeach other; and forming electrically conductive lines connecting theplurality of second, rigid substrates to each other with respectiveelectrically conductive lines, each of the electrically conductive linesbeing flexible and has third modulus of elasticity that is less than thesecond modulus of elasticity.

The method may further include forming an organic light emitting diodeon at least some of the respective ones of the plurality of second,rigid substrates prior to placing each of the plurality of second, rigidsubstrates on the first substrate.

Although the exemplary aspects of the present disclosure have beendescribed in detail with reference to the accompanying drawings, thepresent disclosure is not limited thereto and may be embodied in manydifferent forms without departing from the technical concept of thepresent disclosure. Any embodiment of this disclosure may be combinedwith one or more of any of the other embodiments. Therefore, theexemplary aspects of the present disclosure are provided forillustrative purposes only but not intended to limit the technicalconcept of the present disclosure. The scope of the technical concept ofthe present disclosure is not limited thereto. Therefore, it should beunderstood that the above-described exemplary aspects are illustrativein all aspects and do not limit the present disclosure. The protectivescope of the present disclosure should be construed based on thefollowing claims, and all the technical concepts in the equivalent scopethereof should be construed as falling within the scope of the presentdisclosure.

What is claimed is:
 1. A stretchable display device, comprising: a lowersubstrate; a plurality of island substrates where a plurality of pixelsis defined, spaced apart from each other and disposed on the lowersubstrate and; a plurality of connecting lines electrically connected toa plurality of pads disposed on adjacent island substrates among theplurality of island substrates and disposed on the lower substrate,wherein the plurality of connecting lines has a curved shape; and aplurality of conductive reinforcing members in contact with a portion ofeach connecting line and in direct contact with a lateral side of theplurality of island substrates, wherein the plurality of conductivereinforcing members is disposed between an upper surface of the lowersubstrate and a lower surface of the plurality of connecting lines. 2.The stretchable display device of claim 1, further comprising aplurality of conductive components disposed on each island substrate,wherein the plurality of connecting lines is made of a same material asat least one of the plurality of conductive components.
 3. Thestretchable display device of claim 1, wherein the plurality ofconductive reinforcing members include a base polymer and a liquid metalor a conductive polymer that has conductive particles distributed in thebase polymer.
 4. The stretchable display device of claim 1, wherein theplurality of conductive reinforcing members is disposed only in a regionadjacent to the lateral side of the plurality of island substrates. 5.The stretchable display device of claim 1, wherein the plurality ofconductive reinforcing members is disposed only in a peak area of theplurality of connecting lines.
 6. The stretchable display device ofclaim 1, wherein the plurality of conductive reinforcing members is incontact with a top surface or a bottom surface of the plurality ofconnecting lines.
 7. The stretchable display device of claim 1, whereinthe plurality of connecting lines includes a first sub-connecting lineand a second sub-connecting line disposed on the first sub-connectingline, and the plurality of conductive reinforcing members is disposedbetween the first sub-connecting line and the second sub-connectingline.
 8. The stretchable display device of claim 1, wherein theplurality of connecting lines is in contact with the lower substrate. 9.The stretchable display device of claim 1, further comprising: anadhesive layer covering the plurality of connecting lines; and an uppersubstrate disposed on the adhesive layer and overlapping the lowersubstrate.
 10. The stretchable display device of claim 1, wherein thecurved shape includes a zigzag shape, a sine waveform, or a diamondshape.
 11. The stretchable display device of claim 1, further comprisinga plurality of display elements disposed on the plurality of islandsubstrates, wherein the plurality of display elements is inorganic lightemitting elements or organic light emitting elements.
 12. Thestretchable display device of claim 5, wherein the plurality ofconductive reinforcing members is disposed at an inner edge of the peakarea of the plurality of connecting lines.
 13. A stretchable displaydevice comprising: a lower flexible substrate; a plurality of rigidsubstrates where a plurality of pixels is defined, spaced apart fromeach other and disposed on the lower flexible substrate; a plurality ofconnecting lines electrically connected to a plurality of pads disposedbetween adjacent rigid substrates among the plurality of rigidsubstrates, disposed on the lower substrate, and are made of a samematerial as a plurality of conductive components disposed on theplurality of rigid substrates; and a plurality of conductive flexiblelayers disposed on one of a top surface and a bottom surface of theplurality of connecting lines, wherein the plurality of conductiveflexible layers is disposed only in a region adjacent to a lateral sideof the plurality of rigid substrates or overlap only an area with thelargest amplitude of the connecting lines.
 14. The stretchable displaydevice of claim 13, wherein the plurality of conductive components ismade of s same material as at least one of a gate electrode, a sourceelectrode, and a drain electrode of a thin film transistor, a line, andan electrode of a display element.
 15. The stretchable display device ofclaim 13, wherein the plurality of conductive flexible layers includes abase polymer and conductive particles distributed in the base polymer,or liquid metal.
 16. The stretchable display device of claim 13, whereinthe plurality of conductive flexible layers is disposed to be in contactwith sides of the plurality of rigid substrates or such that theconnecting lines exist between the conductive flexible layers and theplurality of rigid substrates.
 17. The stretchable display device ofclaim 13, further comprising: an adhesive layer covering the pluralityof connecting lines; and an upper substrate disposed on the adhesivelayer and overlapping the lower substrate.
 18. The stretchable displaydevice of claim 16, wherein the plurality of conductive flexible layersis disposed inside the area with the largest amplitude.
 19. Thestretchable display device of claim 18, wherein the plurality ofconnecting lines includes a first sub-connecting line and a secondsub-connecting line disposed on the first sub-connecting line, and theplurality of conductive flexible layers is disposed between the firstsub-connecting line and the second sub-connecting line.